We're new to sailing, and the first question we're often asked is, "Can a sailboat (like a Hunter 36) tip over?" I thought it couldn't because the more horizontal the sail gets, the less rotational moment there is and the keel will right the boat back, or at least to a point of equal moments. If the sail actually touches the water, then things probably change. So how should I answer the question. Is the answer that in theory, the sailboat can't tip over, but in practice it could in very high winds and rough seas?
Can a sailboat capsize?
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Large Wave
I am by no means an expert on the subject, but it is definitely possible to capsize a 36 footer. From what I have read, you need something like a wave whose height is roughly half the length of your boat (18-20 ft) to do it if it hits the boat right. Of course that means you are in out in some rough stuff in a big body of water. If you are out in that kind of stuff, you probably want all the locking cockpit lockers, cabin sealed off, strong rigging, etc - all that nice bluewater boat stuff. The wind alone isn't going to tip the boat over like you mention, but large waves are another story.
I am by no means an expert on the subject, but it is definitely possible to capsize a 36 footer. From what I have read, you need something like a wave whose height is roughly half the length of your boat (18-20 ft) to do it if it hits the boat right. Of course that means you are in out in some rough stuff in a big body of water. If you are out in that kind of stuff, you probably want all the locking cockpit lockers, cabin sealed off, strong rigging, etc - all that nice bluewater boat stuff. The wind alone isn't going to tip the boat over like you mention, but large waves are another story.
Confines of Puget Sound
So I suppose that, practically speaking, its not possible within the confines of an area like Puget Sound by Seattle. It sounds to me that you would only encounter 20 ft waves in the ocean environment.
So I suppose that, practically speaking, its not possible within the confines of an area like Puget Sound by Seattle. It sounds to me that you would only encounter 20 ft waves in the ocean environment.
Don't worry while in Puget Sound
The problem we have around here is looking for some bigger wind to sail in. Most often we just bob. On those rare days of 10-20 knots, terrific. The wind can be pretty nasty when crossing the strait of Juan de Fuca. We got 50 knots one time on our h37.5. Unplesant to say the least, but we didn't get into too much trouble, except the bow did dig in a few times and when it came back up, a wall of water headed for the cockpit. We got a bit wet, and also discovered a few leaky hatches.
The problem we have around here is looking for some bigger wind to sail in. Most often we just bob. On those rare days of 10-20 knots, terrific. The wind can be pretty nasty when crossing the strait of Juan de Fuca. We got 50 knots one time on our h37.5. Unplesant to say the least, but we didn't get into too much trouble, except the bow did dig in a few times and when it came back up, a wall of water headed for the cockpit. We got a bit wet, and also discovered a few leaky hatches.
Capsize and knockdown
are different. Capsize your mast goes into the water which is bad...puts a lot of strain on the rigging and many dismast. A knockdown, your boat goes around and your mast is near water or maybe touching it. This would mean that a good part of your cockpit is in the water and if you don't have your hatches closed, a lot of water can get into the cabin and cause major problems like sinking. A knockdown can happen from a gust of wind. A capsize can happen from a wave larger then the beam of the boat breaking on the boat from the beam. Large rolling waves aren't a problem. It's the steep ones you have to worry about. Usually in those conditions you will have the waves coming from the stern or the bow (good sailing techniques), not the beam, but seas do get confused sometimes and you get them from all kinds of directions. A fixed keel has righing ability so if you do get knocked down because of a hugh gust, like the 90 mph that hit by boat like a brick wall last week while docked, then hopefully you can make your way back onboard and release the sheets so she can right herself before too much water gets into the cabin. Now if you loose your keel, which has happened a few times, then the boat is going over and you can't do anything about it. It's only a matter of time before the boat takes on enough water to sink. Note to self: Stop running aground...that damn keel is going to fall off some day
are different. Capsize your mast goes into the water which is bad...puts a lot of strain on the rigging and many dismast. A knockdown, your boat goes around and your mast is near water or maybe touching it. This would mean that a good part of your cockpit is in the water and if you don't have your hatches closed, a lot of water can get into the cabin and cause major problems like sinking. A knockdown can happen from a gust of wind. A capsize can happen from a wave larger then the beam of the boat breaking on the boat from the beam. Large rolling waves aren't a problem. It's the steep ones you have to worry about. Usually in those conditions you will have the waves coming from the stern or the bow (good sailing techniques), not the beam, but seas do get confused sometimes and you get them from all kinds of directions. A fixed keel has righing ability so if you do get knocked down because of a hugh gust, like the 90 mph that hit by boat like a brick wall last week while docked, then hopefully you can make your way back onboard and release the sheets so she can right herself before too much water gets into the cabin. Now if you loose your keel, which has happened a few times, then the boat is going over and you can't do anything about it. It's only a matter of time before the boat takes on enough water to sink. Note to self: Stop running aground...that damn keel is going to fall off some day
Don't Worry
Wind alone cannot do it. It may knock you down but modern boats are designed so that down-flooding does not occur until well beyond 90°. A very large and steep fronted wave could do it by throwing you over or tripping you over on its front. This happens very rarely to ocean racers and other sailors caught out in a storm. As a relative newcomer you will have turned for home long before the conditions deteriorate this far - I hope. The weather forecast is all important so get one before setting out and don't go if it looks awful, after all sailing is supposed to be an enjoyable pastime and not an endurance trial!.
Wind alone cannot do it. It may knock you down but modern boats are designed so that down-flooding does not occur until well beyond 90°. A very large and steep fronted wave could do it by throwing you over or tripping you over on its front. This happens very rarely to ocean racers and other sailors caught out in a storm. As a relative newcomer you will have turned for home long before the conditions deteriorate this far - I hope. The weather forecast is all important so get one before setting out and don't go if it looks awful, after all sailing is supposed to be an enjoyable pastime and not an endurance trial!.
Not by wind alone.
it usually takes a combination of high wind and high waves to knock a keel boat down. Do not present your beam to high breaking waves. there are various foul weather sailing techniques fpr offshore which you can brush up on different books and articles ; but I think you are talking about the coastal gusts of wind or thunderstorm. As a general rule decrease sail and point into the waves. Put your companionway boards in and harness yourself to the cockpit. Do not run in storm winds as there would be a danger of broaching and you are lengthening the time you will be under the storm's influence. An MOB would be the biggest danger in high winds and rough coastal seas.
it usually takes a combination of high wind and high waves to knock a keel boat down. Do not present your beam to high breaking waves. there are various foul weather sailing techniques fpr offshore which you can brush up on different books and articles ; but I think you are talking about the coastal gusts of wind or thunderstorm. As a general rule decrease sail and point into the waves. Put your companionway boards in and harness yourself to the cockpit. Do not run in storm winds as there would be a danger of broaching and you are lengthening the time you will be under the storm's influence. An MOB would be the biggest danger in high winds and rough coastal seas.
jveatch, I like your boat.
I walk past it to get to mine. You're on E float, right? I'm at E42. The biggest danger on the water isn't from capsizing, it's from the beer that I'll buy for you after checking out each others boats.
I walk past it to get to mine. You're on E float, right? I'm at E42. The biggest danger on the water isn't from capsizing, it's from the beer that I'll buy for you after checking out each others boats.
Yes, a sailboat can capsize
Yes, a sailboat can capsize. Yes, a can of pepsi might fall out of an airplane, land on me and I'd die. Just be prudent, look up, and look both ways before crossing the street. And don't sail in conditions beyond your ability.
Yes, a sailboat can capsize. Yes, a can of pepsi might fall out of an airplane, land on me and I'd die. Just be prudent, look up, and look both ways before crossing the street. And don't sail in conditions beyond your ability.
Ken
I see your point about being prudent in judgment, but I don't agree with your statement "..don't sail in conditions beyond your ability." If that were the case, no one would ever progress beyond sailing in 5 kts of breeze. I have found the best way to learn is to push the envelope a little more each time. In this manner you can gain skill from dealing with ever increasing conditions. After having sailed in steady wind of 35 kts and gusts to 60, I know how to handle those situations and anything less becomes progressively easier. Be prudent by all means, but do push the limits.
I see your point about being prudent in judgment, but I don't agree with your statement "..don't sail in conditions beyond your ability." If that were the case, no one would ever progress beyond sailing in 5 kts of breeze. I have found the best way to learn is to push the envelope a little more each time. In this manner you can gain skill from dealing with ever increasing conditions. After having sailed in steady wind of 35 kts and gusts to 60, I know how to handle those situations and anything less becomes progressively easier. Be prudent by all means, but do push the limits.
Angle of vanishing stability
Not to be too much of a pessimist, but it IS possible to capsize your boat, but a lot of things will play into that. Keep in mind the roll angle wher the 356 (H36) will continue to go over, at factory specs is around 120 degrees. My memory is a little slow tonight, so check that number. Can the wind push you over to that point???YES but not likely. as everyone else has said, it's more likely the combination of wind knocking you down, and a wave rolling you the rest of the way. remember that the specs are rarely good for your boat, and you should re calculate based on your weight as she sits at the dock, fully loaded for your typical cruising. A BREAKING wave directly on our beam would only need to be about 30% of the waterline of the boat, according to Cole's 'Heavy Weather Sailing'. That's 10 ft for our boats. Remember, Breaking. Cole goes on to say he does not beleive it possible for wind alone, or non breaking waves alone to capsize the average cruiser. Here's my concern. When things go bad, it often happens quickly and at the most inopportune time. Being able to think ahead of the boat, and eliminate one thing from the mix will help keep us out of trouble Sailing within your limits is good advice, but it's the unexpected that is usually the problem.
Not to be too much of a pessimist, but it IS possible to capsize your boat, but a lot of things will play into that. Keep in mind the roll angle wher the 356 (H36) will continue to go over, at factory specs is around 120 degrees. My memory is a little slow tonight, so check that number. Can the wind push you over to that point???YES but not likely. as everyone else has said, it's more likely the combination of wind knocking you down, and a wave rolling you the rest of the way. remember that the specs are rarely good for your boat, and you should re calculate based on your weight as she sits at the dock, fully loaded for your typical cruising. A BREAKING wave directly on our beam would only need to be about 30% of the waterline of the boat, according to Cole's 'Heavy Weather Sailing'. That's 10 ft for our boats. Remember, Breaking. Cole goes on to say he does not beleive it possible for wind alone, or non breaking waves alone to capsize the average cruiser. Here's my concern. When things go bad, it often happens quickly and at the most inopportune time. Being able to think ahead of the boat, and eliminate one thing from the mix will help keep us out of trouble
Sailing within your limits is good advice, but it's the unexpected that is usually the problem.
Benny makes a good point
before you flip, someone is probably going to flip out of the boat, unless you are mentally set up with the thinking, that potential MOB is the first concern, sort of "I don't know if we're gonna roll, but if we do I want everyone on board to experience it and not to have to go looking for you."
before you flip, someone is probably going to flip out of the boat, unless you are mentally set up with the thinking, that potential MOB is the first concern, sort of "I don't know if we're gonna roll, but if we do I want everyone on board to experience it and not to have to go looking for you."
Allan, I agree...
Alan, yeah, I agree with you to sail beyond your ability by pushing it a little, raising your abilities in increments. -Ken
Alan, yeah, I agree with you to sail beyond your ability by pushing it a little, raising your abilities in increments. -Ken
See Sail mag stability issue
One or two years ago Sail (or was it Cruising World?) ran at least 2 articles in back to back issues on sailboat stability ratings, and how to calculate your margins. It also clearly showed that most displacement hull boats will have a righting moment that goes to zero and then becomes negative as the boat continues to heel, for whatever reason, well before it reaches 90 degrees--horizontal mast. This means that it WILL capsize given enough of an angle. I ran the numbers for the 356 and it is sort of average, and not bad at all, though there are many older boats with full keels and larger ratios of keel-to-total displacement that are much better. However is is clear that it will continue to heel and capsize when heeled more than about 70 degrees from vertical, even with completely dry sails. The best advice is to monitor the weather channels closely and be prudent--don't go out when very dirty weather is forecast or even likely, unless you are a masochist. If you get caught out in unforecast nightmare conditions put out a sea achor, batten down, and pray. Ivan Bekey H356 Victoria
One or two years ago Sail (or was it Cruising World?) ran at least 2 articles in back to back issues on sailboat stability ratings, and how to calculate your margins. It also clearly showed that most displacement hull boats will have a righting moment that goes to zero and then becomes negative as the boat continues to heel, for whatever reason, well before it reaches 90 degrees--horizontal mast. This means that it WILL capsize given enough of an angle. I ran the numbers for the 356 and it is sort of average, and not bad at all, though there are many older boats with full keels and larger ratios of keel-to-total displacement that are much better. However is is clear that it will continue to heel and capsize when heeled more than about 70 degrees from vertical, even with completely dry sails. The best advice is to monitor the weather channels closely and be prudent--don't go out when very dirty weather is forecast or even likely, unless you are a masochist. If you get caught out in unforecast nightmare conditions put out a sea achor, batten down, and pray. Ivan Bekey H356 Victoria
H36/356 Stability Curve
Ivan - I don't know what Sail's formula's predict, but computing a stability curve is a non-trivial, boiat-specific exercise for naval architects, and I'd be very careful about generic approximations from a magazine. I have a copy of the stability curve I requested from Glenn Henderson when I bought my 2005 H36. Since it's marked Proprietary, I won't post it. However, the AVS (angle of vanishing stability) is 114 degrees, and the area under the negative portion of the curve is a lot less than that above the line. The negative (stay capsized) peak is also smaller than the positive righting moment peak. This is a lot worse than a (very slow) Pacific Seacraft 37's 140 degrees, and not as good as a Tartan 37's 125 degrees. However, it should be compared to the 115 degree AVS required to qualify for some ocean races, and is better than a lot of coastal cruisers. Fair winds.
Ivan - I don't know what Sail's formula's predict, but computing a stability curve is a non-trivial, boiat-specific exercise for naval architects, and I'd be very careful about generic approximations from a magazine. I have a copy of the stability curve I requested from Glenn Henderson when I bought my 2005 H36. Since it's marked Proprietary, I won't post it. However, the AVS (angle of vanishing stability) is 114 degrees, and the area under the negative portion of the curve is a lot less than that above the line. The negative (stay capsized) peak is also smaller than the positive righting moment peak. This is a lot worse than a (very slow) Pacific Seacraft 37's 140 degrees, and not as good as a Tartan 37's 125 degrees. However, it should be compared to the 115 degree AVS required to qualify for some ocean races, and is better than a lot of coastal cruisers. Fair winds.
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