removehtml]Just wondering if the water ballast boats perform like the swing keel boats ? I have to have my boat on a trailer and now own a 23 ft. swing keel boat, but I was thinking of a water ballast type as I can go bigger for the same weight. Thank you AlanError: Error: expected [/URL], but found [/removehtml] instead[/removehtml]
water ballast or swing keel ?
- Thread starter porsche
- Start date
- Status
I've sailed both
I have sailed both and prefer the swing keel boats. The water ballast boats heel much more and are sometimes difficult to sail up wind without 'turning around' in high winds. Both types are inferior to good fixed keel boats going into the wind. Because of my limitations on transport and cheap shallow docking - I will probably always have the swingers. Another option is the O'day type centerboards that have shallow keels with drop down extensions but they often draw too much depth for me.
I have sailed both and prefer the swing keel boats. The water ballast boats heel much more and are sometimes difficult to sail up wind without 'turning around' in high winds. Both types are inferior to good fixed keel boats going into the wind. Because of my limitations on transport and cheap shallow docking - I will probably always have the swingers. Another option is the O'day type centerboards that have shallow keels with drop down extensions but they often draw too much depth for me.
I guess you are talking about weight on trailer.
Yes you can go bigger with less weight. On the water, with the tank full as strongly recommended there should not be a difference in displacement among similar boats. Their sailing characteristics are different. The swing keel will place the center of ballast and righting force vector at approximately 3 ft under the hull while the water tank ballast acts at hull level. The end result is that the water ballsated boat is more tender. Both boats present a compromise in design, your ultimate choice should serve your particular needs.
Yes you can go bigger with less weight. On the water, with the tank full as strongly recommended there should not be a difference in displacement among similar boats. Their sailing characteristics are different. The swing keel will place the center of ballast and righting force vector at approximately 3 ft under the hull while the water tank ballast acts at hull level. The end result is that the water ballsated boat is more tender. Both boats present a compromise in design, your ultimate choice should serve your particular needs.
Tom
How shallow do you want! My hunter 23 draws something like 2 feet, and it is a shoal keel with drop-down centerboard. I love it, because it gives me two different, but very good, boats. With the keel down, i've got 850 lbs of ballast below the hull, plus a 4' deep foil to get me upwind. With it up, i end up with the same righting moment, but now i have a 7' long keel which tracks great in following seas, plus! i don't have to worry about a giant weight hanging from a bronze pin, heavy winches to haul the thing up, locking the keel to avoid it "slamming" and breaking things, or lose any of my already-limited interior space to a keel trunk or water ballast. Brilliant! All at the "cost" of not being able to sail in knee deep water..only thigh deep. Any shallower and your rudder is sticking so far backwards instead of down, that who would WANT to sail in it anyway!
How shallow do you want! My hunter 23 draws something like 2 feet, and it is a shoal keel with drop-down centerboard. I love it, because it gives me two different, but very good, boats. With the keel down, i've got 850 lbs of ballast below the hull, plus a 4' deep foil to get me upwind. With it up, i end up with the same righting moment, but now i have a 7' long keel which tracks great in following seas, plus! i don't have to worry about a giant weight hanging from a bronze pin, heavy winches to haul the thing up, locking the keel to avoid it "slamming" and breaking things, or lose any of my already-limited interior space to a keel trunk or water ballast. Brilliant! All at the "cost" of not being able to sail in knee deep water..only thigh deep. Any shallower and your rudder is sticking so far backwards instead of down, that who would WANT to sail in it anyway!
Avoid water ballast.
I would avoid any boat using either solely or primarily water ballast. This is theoretically unsafe in nearly all serious sailing conditions. Water in tanks does NOT provide positive stability, only neutral as it is the same consistency and weight of the surrounding water (duh). By definition it cannot lower the boat in the water to its designed waterline without literally sinking the boat, however partially. The boat will be sluggish round the roll axis and will tend to heel slowly at first, then with great momentum towards a rollover. In pitch it will slosh fore-and-aft like a fat fishwife waddling to Billingsgate. It will not 'find a groove' and stand stiffly in any weather to speak of. By contrast, a boat with a fixed or swinging ballasted keel uses the placement, weight and shape of the keel to properly stabilize the boat laterally under sail and to establish its sailing/floating waterline according to its true displacement. (Remember that displacement is NOT the weight of the boat on the trailer but rather the volume of the water (measured as weight) it displaces-- sort of like the difference between shipping weight of a sports car and its sprung weight.) Water ballast in boats simply uses too much of something not heavy or dense enough and spreads it over too much of the boat's underwater volume, thus inhibiting true buoyancy, to be effective in what ballast is really supposed to do. Trust me when I say that the PRIMARY objective of a boatbuilder's offering water-ballasted boats is that of cost savings for the builder (just like pricing outboard-powered boats without the motor). Paying 65 cents per pound for something is one thing, but to put 2000 lbs of it into each entry-level unit, and then to pay truck freight on that to the boat factory, and then to ship the finished boat.... You get the idea. I am not talking about racing-- but to back me up, no less than Olin Stephens did say that there are too many design ideas, maybe appropriate in racing-only boats, that are nonsensical for common cruising boats. He meant winged keels; but I say water-ballast is one of them too. (As an aside-- I did say primarily water-ballasted boats are no good. On my H-25 I have collapsible freshwater tanks under the main settee berths, rather like 210 lbs of 'trim ballast' on each side, right in the middle of the boat where it should be. Of course I do not have a way to pump the same 210 lbs from one side to the other on each tack... but that's illegal under common PHRF rules anyway!) People argue with me about empirical evidence FOR water ballast all the time. So, if you do have any doubts about water ballast, lower a bucket half-full of water into a bathtub and observe its stability characteristics when you try to tip it over. Then empty it and tape to its bottom a metal weight that will lower it to the same waterline, and compare it.
I would avoid any boat using either solely or primarily water ballast. This is theoretically unsafe in nearly all serious sailing conditions. Water in tanks does NOT provide positive stability, only neutral as it is the same consistency and weight of the surrounding water (duh). By definition it cannot lower the boat in the water to its designed waterline without literally sinking the boat, however partially. The boat will be sluggish round the roll axis and will tend to heel slowly at first, then with great momentum towards a rollover. In pitch it will slosh fore-and-aft like a fat fishwife waddling to Billingsgate. It will not 'find a groove' and stand stiffly in any weather to speak of. By contrast, a boat with a fixed or swinging ballasted keel uses the placement, weight and shape of the keel to properly stabilize the boat laterally under sail and to establish its sailing/floating waterline according to its true displacement. (Remember that displacement is NOT the weight of the boat on the trailer but rather the volume of the water (measured as weight) it displaces-- sort of like the difference between shipping weight of a sports car and its sprung weight.) Water ballast in boats simply uses too much of something not heavy or dense enough and spreads it over too much of the boat's underwater volume, thus inhibiting true buoyancy, to be effective in what ballast is really supposed to do. Trust me when I say that the PRIMARY objective of a boatbuilder's offering water-ballasted boats is that of cost savings for the builder (just like pricing outboard-powered boats without the motor). Paying 65 cents per pound for something is one thing, but to put 2000 lbs of it into each entry-level unit, and then to pay truck freight on that to the boat factory, and then to ship the finished boat.... You get the idea. I am not talking about racing-- but to back me up, no less than Olin Stephens did say that there are too many design ideas, maybe appropriate in racing-only boats, that are nonsensical for common cruising boats. He meant winged keels; but I say water-ballast is one of them too. (As an aside-- I did say primarily water-ballasted boats are no good. On my H-25 I have collapsible freshwater tanks under the main settee berths, rather like 210 lbs of 'trim ballast' on each side, right in the middle of the boat where it should be. Of course I do not have a way to pump the same 210 lbs from one side to the other on each tack... but that's illegal under common PHRF rules anyway!) People argue with me about empirical evidence FOR water ballast all the time. So, if you do have any doubts about water ballast, lower a bucket half-full of water into a bathtub and observe its stability characteristics when you try to tip it over. Then empty it and tape to its bottom a metal weight that will lower it to the same waterline, and compare it.
The performance lost in a water ballast is minimal relative to the weight saving
which you indicated was an important factor for towing. From cheasapeak bay to key west and lots of points between I have sailed my boat. The "working man's coastal and lake/river explorability" is one of the best traits of water ballast boats. I disagree with the extremity of your statements J II... "It will not 'find a groove' and stand stiffly in any weather to speak of." I guess specifics on the weather would be needed here...I have experienced that my water ballast boat finds a groove and points well...above 12-14 mph wind I flatten sails and move my travler out; above 15 I start the reefing process. Many times, I am going faster than many other boats on the lake or charleston harbor I frequent(not too mention DOZENS of other waters I have been able to explore). You have to ask yourself what you are going to use and how much money you want (can)spend(not what you are dreaming of while browsing cruising world). I am constantly amazed at many ports I sail around how many very nice fixed ballast boats are in the marina and how few of them are on the water. For me, my inexpensive water ballast boat has allowed much exploration (coastal islands/beautiful lakes...)and some pretty competative racing. It points well, close to 40 degrees I believe,and is pretty fast. Well enough and fast enough to go faster than many others...with a very nice groove; as long as you reef above 15 mph winds. I would not go off shore too far or in gale weather...I have been out with about 25 mph winds (lots of whitecaps and foam)could a keel boat have handled it better, probably...were many of them out there...no, not where i sail anyhow...i'm sure it would be different on san francisco bay!
which you indicated was an important factor for towing. From cheasapeak bay to key west and lots of points between I have sailed my boat. The "working man's coastal and lake/river explorability" is one of the best traits of water ballast boats. I disagree with the extremity of your statements J II... "It will not 'find a groove' and stand stiffly in any weather to speak of." I guess specifics on the weather would be needed here...I have experienced that my water ballast boat finds a groove and points well...above 12-14 mph wind I flatten sails and move my travler out; above 15 I start the reefing process. Many times, I am going faster than many other boats on the lake or charleston harbor I frequent(not too mention DOZENS of other waters I have been able to explore). You have to ask yourself what you are going to use and how much money you want (can)spend(not what you are dreaming of while browsing cruising world). I am constantly amazed at many ports I sail around how many very nice fixed ballast boats are in the marina and how few of them are on the water. For me, my inexpensive water ballast boat has allowed much exploration (coastal islands/beautiful lakes...)and some pretty competative racing. It points well, close to 40 degrees I believe,and is pretty fast. Well enough and fast enough to go faster than many others...with a very nice groove; as long as you reef above 15 mph winds. I would not go off shore too far or in gale weather...I have been out with about 25 mph winds (lots of whitecaps and foam)could a keel boat have handled it better, probably...were many of them out there...no, not where i sail anyhow...i'm sure it would be different on san francisco bay!
How much weight savings
Hunter 240 2,300 lb dry 3,600 full ballast tank Hunter 23.5 2000 lb dry 3000 lb full tank Hunter 23 2,450 lb, iron keel Both carry similar sail area, are of similar length and shape. The 23 sits about a foot higher up on the trailer, which IS of a concern when trailering. But weight savings? Probably more likely to attribute them to savings in the lay-up schedule, or the rig (the 23's mast and boom are much heavier). Also, the same sails, pushing a boat with 50% more displacement? BTW: I have no qualms holding my boat over at 45 degrees. It only gets stiffer from there.
Hunter 240 2,300 lb dry 3,600 full ballast tank Hunter 23.5 2000 lb dry 3000 lb full tank Hunter 23 2,450 lb, iron keel Both carry similar sail area, are of similar length and shape. The 23 sits about a foot higher up on the trailer, which IS of a concern when trailering. But weight savings? Probably more likely to attribute them to savings in the lay-up schedule, or the rig (the 23's mast and boom are much heavier). Also, the same sails, pushing a boat with 50% more displacement? BTW: I have no qualms holding my boat over at 45 degrees. It only gets stiffer from there.
The purpose of ballast is to keep the boat on its keel
Water ballast only starts to exert is influence when it is lifted above the load water line. An iron keel is not by definition ballast, it is a functional essential working part of the boat. However it exerts is righting influence whenever the center of gravity is not in vertical alignment with the center of buoyancy. Sailing merchant ships were built without ballast. The cargo was needed for stability. Modern tankers travel in ballast when not carrying cargo(crude oil or molasses or whatever) The sailing ships of the past that traded with the American colonies sailed in ballast from Europe and loaded cargo in American ports. The ballast was often granite paving stones that the American governors specified and then chaged for off loading and disposal. Water is ballast of choice only because it is free and easily dumped.
Water ballast only starts to exert is influence when it is lifted above the load water line. An iron keel is not by definition ballast, it is a functional essential working part of the boat. However it exerts is righting influence whenever the center of gravity is not in vertical alignment with the center of buoyancy. Sailing merchant ships were built without ballast. The cargo was needed for stability. Modern tankers travel in ballast when not carrying cargo(crude oil or molasses or whatever) The sailing ships of the past that traded with the American colonies sailed in ballast from Europe and loaded cargo in American ports. The ballast was often granite paving stones that the American governors specified and then chaged for off loading and disposal. Water is ballast of choice only because it is free and easily dumped.
The attractiveness of a water ballasted boat
lies in that by releasing the weight of the ballast it will trailer like a lighter boat. Boat manufacturers saw that there was a market out there for people that wanted a larger more comfortable boat but where constrained by the limitations of trailering. Trailering seems to have a big cutoff in cost at the 6,000 to 7,000 lbs level. Under that weight you can use a dual purpose vehicle like a big family sedan, a van or pickup truck. The trailer can be a twin axle lighter rig with no need for a tongue extender. Over that weight limit you may need a dedicated vehicle to tow in the form of a 3/4 ton truck or van with perhaps a heavier three axle trailer. A keeled boat includying the short keel/center board combo may need steeper, longer ramps to launch from and perhaps a tongue extender. These requirements may limit the number of ramps the boats could be launched from. Long keel boats may require a lift. The design had some serious drawbacks in boat stability, safety and reliability. There were also some serious accidents with loss of life for failures to properly fill the ballast tank. This has translated into liability for the manufacturers and discontent from consumers. The manufacturers are now getting away from that design and incorporating the short keel/ centerboard combo. Improvements in towing capacity by some dual purpose vehicles and lighter stronger trailers now allow the manufacturers to service that market segment. This is not to say that properly maintained and operated a water ballast boat can be safe and enjoyable for inland protected waters.
lies in that by releasing the weight of the ballast it will trailer like a lighter boat. Boat manufacturers saw that there was a market out there for people that wanted a larger more comfortable boat but where constrained by the limitations of trailering. Trailering seems to have a big cutoff in cost at the 6,000 to 7,000 lbs level. Under that weight you can use a dual purpose vehicle like a big family sedan, a van or pickup truck. The trailer can be a twin axle lighter rig with no need for a tongue extender. Over that weight limit you may need a dedicated vehicle to tow in the form of a 3/4 ton truck or van with perhaps a heavier three axle trailer. A keeled boat includying the short keel/center board combo may need steeper, longer ramps to launch from and perhaps a tongue extender. These requirements may limit the number of ramps the boats could be launched from. Long keel boats may require a lift. The design had some serious drawbacks in boat stability, safety and reliability. There were also some serious accidents with loss of life for failures to properly fill the ballast tank. This has translated into liability for the manufacturers and discontent from consumers. The manufacturers are now getting away from that design and incorporating the short keel/ centerboard combo. Improvements in towing capacity by some dual purpose vehicles and lighter stronger trailers now allow the manufacturers to service that market segment. This is not to say that properly maintained and operated a water ballast boat can be safe and enjoyable for inland protected waters.
Time
Wonder how long these boats will stand up with water on both sides of the fiberglass. The 26X across from me has thousands of blisters, just after two 6 month seasons.
Wonder how long these boats will stand up with water on both sides of the fiberglass. The 26X across from me has thousands of blisters, just after two 6 month seasons.
It can be very enjoyable for coastal waters as well!
Many say macgregor (mine is a 26s) water ballast boats are great "lake" boats (or inland protected boats I guess, but lake seems to be the deragatory term of choice). They can sit there talking while others are out coastal doing! I had one guy at a boatable bar a bit west of pensacola tell me macggregors were only good for lakes...while I pointed to my boat docked there after a 15 mile sail OFF THE COAST from an awesome SALT WATER anchorage were we had spent the past 4 wonderful days. I'm not saying the cheaper built water ballsat boats are not without compromise...but I am saying that so mnay enjoy propping themselves up by putting others down that they will dispell incorrect or negatively amplified dogma they have heard without any firsthand knowledge whatsoever... My experience has indicated that I do with my boat what the MAJORITY of other boaters do...fly around off the coast or inland waters and then back to the dock. When I plan some serious cruising I will not be on a water ballast boat...till then I will keep sailing my boat in waters and winds others TALK about it not being able to do! I actually talked with another guy at a dock...sitting there drinking beer telling me how bad my boat was... I said come on out and lets play (he was on a heavier more durable and more stable catalina 25) he said "naaw, too windy for me". It was whitecapping...but probably not over 20. I left him at the dock. A Sailors ability and desire, generally, is what limits his coastal explorations...with, as any sailor in todays world should know, a healthy consideration of what the weather forcast is and some storm tactics! I know the loss of life accident you wrote of Benny...and it was totally tragic operator judgement error.
Many say macgregor (mine is a 26s) water ballast boats are great "lake" boats (or inland protected boats I guess, but lake seems to be the deragatory term of choice). They can sit there talking while others are out coastal doing! I had one guy at a boatable bar a bit west of pensacola tell me macggregors were only good for lakes...while I pointed to my boat docked there after a 15 mile sail OFF THE COAST from an awesome SALT WATER anchorage were we had spent the past 4 wonderful days. I'm not saying the cheaper built water ballsat boats are not without compromise...but I am saying that so mnay enjoy propping themselves up by putting others down that they will dispell incorrect or negatively amplified dogma they have heard without any firsthand knowledge whatsoever... My experience has indicated that I do with my boat what the MAJORITY of other boaters do...fly around off the coast or inland waters and then back to the dock. When I plan some serious cruising I will not be on a water ballast boat...till then I will keep sailing my boat in waters and winds others TALK about it not being able to do! I actually talked with another guy at a dock...sitting there drinking beer telling me how bad my boat was... I said come on out and lets play (he was on a heavier more durable and more stable catalina 25) he said "naaw, too windy for me". It was whitecapping...but probably not over 20. I left him at the dock. A Sailors ability and desire, generally, is what limits his coastal explorations...with, as any sailor in todays world should know, a healthy consideration of what the weather forcast is and some storm tactics! I know the loss of life accident you wrote of Benny...and it was totally tragic operator judgement error.
Mac boats/////
My swing keel V222 is a tremendous boat, and would probably sail it anywhere!!!! When I first got the boat there were several areas of concern, where the fiberglass hull was indeed very weak..... flexed way to much.... I took some 2X2s and fiberglassed ribbing into those areas, and now have a very very strong hull!!!! No flexing anymore!!!!! I think a Mac, with alittle beefing up of the specs, can be made into a boat just as good and strong as any other stock boat out there!!! Too, I added more ballast to enhance stability!!!! Now as to water ballast verses a swing keel,,, I would say the swing keel will be better under sail,,, but indeed it is heavier to pull about on your trailer!!!! With every choice comes compromise!!!!
My swing keel V222 is a tremendous boat, and would probably sail it anywhere!!!! When I first got the boat there were several areas of concern, where the fiberglass hull was indeed very weak..... flexed way to much.... I took some 2X2s and fiberglassed ribbing into those areas, and now have a very very strong hull!!!! No flexing anymore!!!!! I think a Mac, with alittle beefing up of the specs, can be made into a boat just as good and strong as any other stock boat out there!!! Too, I added more ballast to enhance stability!!!! Now as to water ballast verses a swing keel,,, I would say the swing keel will be better under sail,,, but indeed it is heavier to pull about on your trailer!!!! With every choice comes compromise!!!!
Nice to see bio and Dennis out of the Sails Call lounge
for a spell. There was an accident on, I believe a Mac 26 X on Lake Champlain on a fourth of July celebration several years back. The guy had not opened up the water ballast and the boat tipped and a child or 2 drowned leaving a whole lot of finger pointing going on. A very sad accident resulting in 2 drownings. The fact of the matter is that what this guy did was akin to taking your boat out without putting in the drain plug or attaching the fuel line. Well, not really akin but with a water ballast boat this is the FIRST order of business once in the water. There are some nut-jobs out there that intentionally sail with a partially filled ballast to get extra speed at the cost of less righting ability. I suppose in light winds this might be fun but NOT when taking people out to see fireworks or when the wind pipes up. I friend of mine bought a Mac 26 S (same as bio's boat) and we sailed it outside the Colregs demarcation line and I was quite impressed with the speeds we could reach when we had around 15 kts of wind (6.8 kts. on GPS). A little weather helm but that is why the jib (on his boat) looks kind of small. The small jib reduces the forces pushing the boat over yet still pushes her forward. A bigger jib would be scary in any kind of decent wind. For overall ease of trailering I like the water ballast (as long as you remember to fill it after launch and drain it once out). As Benny (and others) pointed out this boat can be launched in about 3' of water which is a lot LESS than required for a more robust hull with a swing keel. Every boat has it's trade-offs. The other thing I liked about the Mac 26S is that there is sleeping room for 6 in the 'tween deck (cabin) but not that much headroom (hence the pop-top). My 27' Tartan has only berths for 5 adults. You should look at every type of boat that is out there that fits your intended purposes and NOT be swayed by others negative opinions (many of which are echoed second hand).
for a spell. There was an accident on, I believe a Mac 26 X on Lake Champlain on a fourth of July celebration several years back. The guy had not opened up the water ballast and the boat tipped and a child or 2 drowned leaving a whole lot of finger pointing going on. A very sad accident resulting in 2 drownings. The fact of the matter is that what this guy did was akin to taking your boat out without putting in the drain plug or attaching the fuel line. Well, not really akin but with a water ballast boat this is the FIRST order of business once in the water. There are some nut-jobs out there that intentionally sail with a partially filled ballast to get extra speed at the cost of less righting ability. I suppose in light winds this might be fun but NOT when taking people out to see fireworks or when the wind pipes up. I friend of mine bought a Mac 26 S (same as bio's boat) and we sailed it outside the Colregs demarcation line and I was quite impressed with the speeds we could reach when we had around 15 kts of wind (6.8 kts. on GPS). A little weather helm but that is why the jib (on his boat) looks kind of small. The small jib reduces the forces pushing the boat over yet still pushes her forward. A bigger jib would be scary in any kind of decent wind. For overall ease of trailering I like the water ballast (as long as you remember to fill it after launch and drain it once out). As Benny (and others) pointed out this boat can be launched in about 3' of water which is a lot LESS than required for a more robust hull with a swing keel. Every boat has it's trade-offs. The other thing I liked about the Mac 26S is that there is sleeping room for 6 in the 'tween deck (cabin) but not that much headroom (hence the pop-top). My 27' Tartan has only berths for 5 adults. You should look at every type of boat that is out there that fits your intended purposes and NOT be swayed by others negative opinions (many of which are echoed second hand).
10 months, 5200NM
The wife and I have been very happy with our 260. We have just completed America's Great Loop. During the trip we spent every night except one on the boat. What more can you ask from a sailboat, sailed the ICW (both Atlantic and Gulf), Hudson River, Erie canal, Great Lakes to Chicago, down the River Systems to the Gulf. Averaged 35 NMs a day and was and am very comfortable. We are working on a 39ft Corbin while living on our 260. Love the boat. John and Anita S/V Baums Rush S/V Bright Eyes
The wife and I have been very happy with our 260. We have just completed America's Great Loop. During the trip we spent every night except one on the boat. What more can you ask from a sailboat, sailed the ICW (both Atlantic and Gulf), Hudson River, Erie canal, Great Lakes to Chicago, down the River Systems to the Gulf. Averaged 35 NMs a day and was and am very comfortable. We are working on a 39ft Corbin while living on our 260. Love the boat. John and Anita S/V Baums Rush S/V Bright Eyes
Water Ballast- the usual fallacious arguments
It is sort of interesting to see the same old arguments against water ballast trotted out every time someone new asks about it- sort of interesting only because of the errors many of them contain. "Water in tanks does NOT provide positive stability, only neutral as it is the same consistency and weight of the surrounding water (duh). By definition it cannot lower the boat in the water to its designed waterline without literally sinking the boat, however partially." What does this mean? I have a water-ballasted boat; when the ballast tank is full, the boat floats at its design waterline- the boat is not sunk, no more than is another boat with a piece of cast iron or lead in the bottom of it. This is nonsense. "The boat will be sluggish round the roll axis and will tend to heel slowly at first, then with great momentum towards a rollover. In pitch it will slosh fore-and-aft like a fat fishwife waddling to Billingsgate. It will not 'find a groove' and stand stiffly in any weather to speak of." If the ballast tank is filled and closed, the water in it cannot "slosh" either fore and aft or side to side; therefore, the weight of the ballast remains in the same position in the boat all of the time. The boat may heel more than some others because of the amount and placement of the ballast, but the implication that water ballast causes problems by "sloshing around" seems to be wishful thinking on the part of someone trying to find fault, regardless of any lack of basis in fact. "By contrast, a boat with a fixed or swinging ballasted keel uses the placement, weight and shape of the keel to properly stabilize the boat laterally under sail and to establish its sailing/floating waterline according to its true displacement. (Remember that displacement is NOT the weight of the boat on the trailer but rather the volume of the water (measured as weight) it displaces-- sort of like the difference between shipping weight of a sports car and its sprung weight.)" Does this mean that a water-ballasted boat doesn't float at a line determined by its displacement? A lot of physics teachers are going to be surprised at this one. "Water ballast in boats simply uses too much of something not heavy or dense enough and spreads it over too much of the boat's underwater volume, thus inhibiting true buoyancy, to be effective in what ballast is really supposed to do." I suppose this means that water-ballasted boats just fall over. This is strictly opinion. "Trust me when I say that the PRIMARY objective of a boatbuilder's offering water-ballasted boats is that of cost savings for the builder (just like pricing outboard-powered boats without the motor). Paying 65 cents per pound for something is one thing, but to put 2000 lbs of it into each entry-level unit, and then to pay truck freight on that to the boat factory, and then to ship the finished boat.... You get the idea." The track record for rational explanations so far does not encourage trust here, particularly when most people with knowledge of water ballast understand that the primary purpose is to enable easier trailering of a larger boat. The fact that the boat is less expensive to build and buy is a consideration- it enables a lot of people to sail who could not afford other construction types. "I am not talking about racing-- but to back me up, no less than Olin Stephens did say that there are too many design ideas, maybe appropriate in racing-only boats, that are nonsensical for common cruising boats. He meant winged keels; but I say water-ballast is one of them too." By your own words, Olin Stephens DID NOT back you up; he was referring to winged keels; you were the one who attempted to apply his statement to water ballast. "People argue with me about empirical evidence FOR water ballast all the time. So, if you do have any doubts about water ballast, lower a bucket half-full of water into a bathtub and observe its stability characteristics when you try to tip it over. Then empty it and tape to its bottom a metal weight that will lower it to the same waterline, and compare it." Let's have a realistic comparison here, not one biased for a particular outcome. Tape a CLOSED CONTAINER of water in the bottom of the bucket to simulate the ballast tank; after all, the ballast doesn't slosh all over the inside of the boat hull, it resides in a closed tank (we've been here before, haven't we?). Then you can compare it to the bucket with the metal weight taped in it. JCII, please understand that I have nothing personal against you, and that I respect your right to your opinion wrt water ballast or anything else. However, the arguments that you have put forth to justify, validate, or explain your position are not based on physical principles, and some are based on erroneous assumptions. I would hate to see someone make a decision based on inaccurate information. When someone asks for information, each of us has an opportunity to share both our knowledge and our opinions. Honesty should compel us to separate and identify the two. What we present as fact or knowledge should be supported or at least supportable by facts and physical principles. Our opinions should be presented as opinion or personal preference. I agree that water ballast is not best for everyone, and that there are some valid reasons why some people don't want it (but I didn't see those reasons here). I don't know where you got your information, but I have seen much of it before. I have also read your most impressive bio, and I would have expected a more careful verification of information before using it.
It is sort of interesting to see the same old arguments against water ballast trotted out every time someone new asks about it- sort of interesting only because of the errors many of them contain. "Water in tanks does NOT provide positive stability, only neutral as it is the same consistency and weight of the surrounding water (duh). By definition it cannot lower the boat in the water to its designed waterline without literally sinking the boat, however partially." What does this mean? I have a water-ballasted boat; when the ballast tank is full, the boat floats at its design waterline- the boat is not sunk, no more than is another boat with a piece of cast iron or lead in the bottom of it. This is nonsense. "The boat will be sluggish round the roll axis and will tend to heel slowly at first, then with great momentum towards a rollover. In pitch it will slosh fore-and-aft like a fat fishwife waddling to Billingsgate. It will not 'find a groove' and stand stiffly in any weather to speak of." If the ballast tank is filled and closed, the water in it cannot "slosh" either fore and aft or side to side; therefore, the weight of the ballast remains in the same position in the boat all of the time. The boat may heel more than some others because of the amount and placement of the ballast, but the implication that water ballast causes problems by "sloshing around" seems to be wishful thinking on the part of someone trying to find fault, regardless of any lack of basis in fact. "By contrast, a boat with a fixed or swinging ballasted keel uses the placement, weight and shape of the keel to properly stabilize the boat laterally under sail and to establish its sailing/floating waterline according to its true displacement. (Remember that displacement is NOT the weight of the boat on the trailer but rather the volume of the water (measured as weight) it displaces-- sort of like the difference between shipping weight of a sports car and its sprung weight.)" Does this mean that a water-ballasted boat doesn't float at a line determined by its displacement? A lot of physics teachers are going to be surprised at this one. "Water ballast in boats simply uses too much of something not heavy or dense enough and spreads it over too much of the boat's underwater volume, thus inhibiting true buoyancy, to be effective in what ballast is really supposed to do." I suppose this means that water-ballasted boats just fall over. This is strictly opinion. "Trust me when I say that the PRIMARY objective of a boatbuilder's offering water-ballasted boats is that of cost savings for the builder (just like pricing outboard-powered boats without the motor). Paying 65 cents per pound for something is one thing, but to put 2000 lbs of it into each entry-level unit, and then to pay truck freight on that to the boat factory, and then to ship the finished boat.... You get the idea." The track record for rational explanations so far does not encourage trust here, particularly when most people with knowledge of water ballast understand that the primary purpose is to enable easier trailering of a larger boat. The fact that the boat is less expensive to build and buy is a consideration- it enables a lot of people to sail who could not afford other construction types. "I am not talking about racing-- but to back me up, no less than Olin Stephens did say that there are too many design ideas, maybe appropriate in racing-only boats, that are nonsensical for common cruising boats. He meant winged keels; but I say water-ballast is one of them too." By your own words, Olin Stephens DID NOT back you up; he was referring to winged keels; you were the one who attempted to apply his statement to water ballast. "People argue with me about empirical evidence FOR water ballast all the time. So, if you do have any doubts about water ballast, lower a bucket half-full of water into a bathtub and observe its stability characteristics when you try to tip it over. Then empty it and tape to its bottom a metal weight that will lower it to the same waterline, and compare it." Let's have a realistic comparison here, not one biased for a particular outcome. Tape a CLOSED CONTAINER of water in the bottom of the bucket to simulate the ballast tank; after all, the ballast doesn't slosh all over the inside of the boat hull, it resides in a closed tank (we've been here before, haven't we?). Then you can compare it to the bucket with the metal weight taped in it. JCII, please understand that I have nothing personal against you, and that I respect your right to your opinion wrt water ballast or anything else. However, the arguments that you have put forth to justify, validate, or explain your position are not based on physical principles, and some are based on erroneous assumptions. I would hate to see someone make a decision based on inaccurate information. When someone asks for information, each of us has an opportunity to share both our knowledge and our opinions. Honesty should compel us to separate and identify the two. What we present as fact or knowledge should be supported or at least supportable by facts and physical principles. Our opinions should be presented as opinion or personal preference. I agree that water ballast is not best for everyone, and that there are some valid reasons why some people don't want it (but I didn't see those reasons here). I don't know where you got your information, but I have seen much of it before. I have also read your most impressive bio, and I would have expected a more careful verification of information before using it.
Well Stated Paul
Those who speak of sloshing or use the bucket half full of water arguement fail to understand the reality of a water ballast tank. The bucket arguement is only valid if they solidly freeze the water to the bottom of the bucket. They overlook this, and have zero understanding of the "free surface effect". Paul, may you always sail with your tanks well filled and secure. Dennis W. S/V FullSailed ps: previous owner M26S
Those who speak of sloshing or use the bucket half full of water arguement fail to understand the reality of a water ballast tank. The bucket arguement is only valid if they solidly freeze the water to the bottom of the bucket. They overlook this, and have zero understanding of the "free surface effect". Paul, may you always sail with your tanks well filled and secure. Dennis W. S/V FullSailed ps: previous owner M26S
Thank you Paul
Thank you Paul for your explanation on the water ballest system. I had realized all that you had said early on and have decided to look more into the water ballest boats as my next. I have been known to be to spontaneous in the past with my decisions so this time I will take my time. I want to thank you all for your responses. Alan
Thank you Paul for your explanation on the water ballest system. I had realized all that you had said early on and have decided to look more into the water ballest boats as my next. I have been known to be to spontaneous in the past with my decisions so this time I will take my time. I want to thank you all for your responses. Alan
How is Lake Tillery?
Many of the lakes and reservoirs in my area (just east of Raleigh) are low due to the drought. How are things around your lake? I have been by Lake Tillery and Badin Lake many times, although I have never boated on either. Have camped several times at Morrow Mountain SP with scout troop and family. Nice country! - Paul
Many of the lakes and reservoirs in my area (just east of Raleigh) are low due to the drought. How are things around your lake? I have been by Lake Tillery and Badin Lake many times, although I have never boated on either. Have camped several times at Morrow Mountain SP with scout troop and family. Nice country! - Paul
I keep thinking
about the physics going on here. If we take said bucket with the water in a closed container (as it very well should be), the "Ballast" is going to be completely submerged - the waterline of the bucket is higher up than the ballast line. Is it fact that no righting moment can be created until the water is lifted above the surface of the water? Becuase that's not true - the ballasted boat has a center of gravity, defined by the location of the keel or ballast tank. If theres no sloshing around, this CG doesn't change. On an even waterline, CG is directly above center of buoyancy. As a boat rolls or pitches, the CG moves, the CB moves, and the distance is essentially the righting moment, because the boat's weight hasn't changed. For a shoal-keel boat, the CG is perhaps just below the waterline. With the ballast moved higher up into the boat, we'll place the CG just above the waterline. Noting that similar sized boats, water or keel ballast, tend to have similar sail areas, they probably have similar righting momenst. Looking at a hunter 240 vs a 23, I see 1300 lbs of water to 800 lbs of iron, for a similar righting moment. This implies to me that IN the water, water ballast will add ~ 50% to your ballast weight to maintain the same sail-carrying ability. I'll leave those actual calculations to the manufacturers for now. I'll make a baseline - 2400 lbs, 1/3 ballast. Adding water ballast to this boat, i need 1200 lbs of water. My displacement in the water goes up by ~15%, my weight out of the water goes down by ~30%, for the same righting moment at "normal" heeling angles. You also get a foot less draft to play with, as a side bonus. --I'm just going to make a guess - nobody wants to be in a water ballast boat in weather where they are expecting knockdowns or possible capsizing. So we don't need to talk about THOSE angles.
about the physics going on here. If we take said bucket with the water in a closed container (as it very well should be), the "Ballast" is going to be completely submerged - the waterline of the bucket is higher up than the ballast line. Is it fact that no righting moment can be created until the water is lifted above the surface of the water? Becuase that's not true - the ballasted boat has a center of gravity, defined by the location of the keel or ballast tank. If theres no sloshing around, this CG doesn't change. On an even waterline, CG is directly above center of buoyancy. As a boat rolls or pitches, the CG moves, the CB moves, and the distance is essentially the righting moment, because the boat's weight hasn't changed. For a shoal-keel boat, the CG is perhaps just below the waterline. With the ballast moved higher up into the boat, we'll place the CG just above the waterline. Noting that similar sized boats, water or keel ballast, tend to have similar sail areas, they probably have similar righting momenst. Looking at a hunter 240 vs a 23, I see 1300 lbs of water to 800 lbs of iron, for a similar righting moment. This implies to me that IN the water, water ballast will add ~ 50% to your ballast weight to maintain the same sail-carrying ability. I'll leave those actual calculations to the manufacturers for now. I'll make a baseline - 2400 lbs, 1/3 ballast. Adding water ballast to this boat, i need 1200 lbs of water. My displacement in the water goes up by ~15%, my weight out of the water goes down by ~30%, for the same righting moment at "normal" heeling angles. You also get a foot less draft to play with, as a side bonus. --I'm just going to make a guess - nobody wants to be in a water ballast boat in weather where they are expecting knockdowns or possible capsizing. So we don't need to talk about THOSE angles.
Ditto soloing and paul on WB
I've sailed many years and many miles in H240's and 260's and been on some pretty large and lumpy waters. This spring I will head for the Sea of Cortez for the 3rd time with my easy to trailer, easy to launch 260 for a month. Counting the days....
I've sailed many years and many miles in H240's and 260's and been on some pretty large and lumpy waters. This spring I will head for the Sea of Cortez for the 3rd time with my easy to trailer, easy to launch 260 for a month. Counting the days....
- Status