You want the keel that best fits your needs. If you race and shallow water is not a problem, then you want a deep fin keel for best windward performance and speed. If you race where there are weeds, then a keel with a straight up and down leading edge will be a problem unless you have a kelp-cutter. Then you would consider a fin keel that slants away to not pick up weeds. If you are sailing in SW Florida or the Bahamas, then a shoal keel is best so you aren't running aground all the time. 5.5' is considered best as that will allow you to go most anywhere when gunkholing, etc., but I have sailed with a 6.5' draft all over the Bahamas and sometimes had to wait for high tide. Another alternative is a shoal draft with a centerboard so you are good to go in shallow water, but then when in deep water, the centerboard will aid windward performance. Shoal draft keels generally do not enable a boat to point to weather. There is an old sailing statement that "gentlemen don't go to weather". That is because, back in that day, boat designs didn't allow good windward performance, but now that has changed and going to weather now is gentlemanly too. The old full keel with attached rudder is a very sea-kindly configuration (like those found on a Cape Dory, for example). Pointing is not very good and backing under power with that sort of rudder is not very good either (the boat backs better one way, but not the other). But, when you run aground, little damage can be expected and it is predictable as to how the boat will react. Bilges are very deep in this type of keel, so water, however it finds its way to the bilge stays low and even when heeling a lot, it stays low and doesn/t migrate into areas you wish to stay dry. When sailing in heavy seas, the full keel is more sea-kindly and comfortable (if that is possible - you always want to pick your weather window and not find yourself in bad seas, if possible - when cruising anyway). That is why Island Packet type boats are popular in the Bahamas and Caribbean. Big, heavy, slow and tough. Not great sailing boats speed wise, nor do they point very well, but sailors like them. Winged keels became popular with the Australian America's Cup win after decades of U.S.A. victories starting in England in 1851 or whenever it was. So, lots of production boat manufacture's designed their keels that way. It was supposed to be a configuration where a shoal keel could experience the best lift possible with the wing for better windward performance, but it doesn't work very well and many sailors complain about how it is more like an anchor when you run aground in sandy or soft conditions which makes it harder to break away. The Australian boat also had a very deep keel in addition to the wings, and so deep is still best for windward performance. I'm running off the page here. Does that mean my typing will not be visible? I might want to post this just in case.
Which type of keel do you prefer?
- Thread starter Curious Sailor
- Start date
Has anyone had any experience with twin bilge keels, they are very popular in the UK and I have seen a handful around here? They look very practical for shallow sailing and doing your own work on the beach. I imagine that their sailing capabilities would suffer due to the additional drag...just wondering?
In this neck of the woods given our fifteen foot tides you would think their popularity would be greater, they must lack in windward performance or perhaps stability?
The one thing that has been left out of this conversation is how they are attached. I personally like the keel box attachment type on my Hunter. It gives me a 2+ deep bilge where I can store large pumps and also an alarm that can go off well before the water reaches the hull (important for finding the leak). It also provides a flexibility to absorb some of the shock when running aground so the keel bolts don't take all the pressure. It also concentrates the weight lower making it more effective.
Mine is a 5' draft on a 37er with wing Bulb combo that yes, when it hits, it sticks and is very hard to get off so I am very careful these days about shallow water. On the other side though, I can get into parts of the anchorage others can't and that gives me a nicer spot many times.
There have been a quiet a few times I've wondered what it would be like if I had a heavy full keeled boat but they just perform way too bad for me to buy one. I personally like sailing in light winds so it is good I have a boat that sails good in light winds and my keel box keel gives me that with other benefits.
Mine is a 5' draft on a 37er with wing Bulb combo that yes, when it hits, it sticks and is very hard to get off so I am very careful these days about shallow water. On the other side though, I can get into parts of the anchorage others can't and that gives me a nicer spot many times.
There have been a quiet a few times I've wondered what it would be like if I had a heavy full keeled boat but they just perform way too bad for me to buy one. I personally like sailing in light winds so it is good I have a boat that sails good in light winds and my keel box keel gives me that with other benefits.
Lol.. True!A friend of mine in FL once told me [as he was dragging me off of a sand bar]: "If you don't run aground at least once a year, you're not sailing enough!"
I prefer a shoal draft wing (bulb) keel. I've been hard aground only once in mud (KY lake with 5 foot keel depth) with no damage, but soft groundings in SW Florida sand were no problem to get off and soft mud a couple of times has been the same way. I think any hard grounding with my keel is going to be hard to get off. I've sailed in full keel boats and my shoal draft bulb performed as well if not better in comfort than the full keel boats I have been on.
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Here is a good video of shallow draft ocean going boats from Delphia - versions that were purpose build for their ability in terms of what certain markets require. Is it perfect? No. Does it fulfil the owners' requirements - absolutely. Check it out.
Something not talked about is how much fore to aft width down low. My first monohull had a shoal draft with a small swing center board. If a gust hit you, it would knock you down fast. My current boat has the same amount of ballast 6 inches more draft, but gives you all day to respond to a wind gust. some have suggested my current boat is tender, with only 350 lbs of ballast, however the swing keel is the same width (fore to aft) all the way to the bottom. So when a wind gust hits, even though there is not much weight, it must move a lot of water to heel the boat over. This gives you much more time to let out the traveler or main sheet to prevent getting knocked down. Can't think of any disadvantage to this aspect. This boat sails up wind like no body's business.
Indeed. Normally a boat with 2 (or more) keel configs will name the shallowest one 'shoal draft'. But that can be tricky as well. My 35 footer with the performace keel draws 7.5 feet. The so-called shoal keel version, a inch short of 6 feet. Not shoal in most peoples books.
Like many have said. Here on the west coast of FL., you are either aground or getting ready to go aground. Several years ago, my boat took a lightning strike that killed the depth sounder. Now, I have been sailing these waters for fourty years and thought, "I'll get it replaced someday". A year goes by and after sailing almost every weekend I never touched bottom. The Admiral keeps harping about the need to replace it. So, I do just that. Next time out, Admiral says, "I think we are in shallow water." I reply "No, the sounder is just acting up due to silt." Well, we did have a nice sunset as we waited for the tide to come back up.
Just additions to some of the comments above. Twin keels - correct on the comment with very high tides as when they go out, then boats with twin keels can sit on the bottom upright (not heeled over) so that live aboards can still live aboard on an even keel. But also, where these boats are made, like England, they have the North Sea, which is a very difficult body of water and sailing can be quite rough, with big seas, big winds, etc. and the extra keel ballast only helps keep the boat more comfortable. The downside is when those boats are brought to places to be sailed on inland lakes, they are very slow especially in light air and not very nimble. Westerly made a number of boats with twin keels. Someone else mentioned the fore and aft configuration of shoal keels. There are a number of reasons for stability differences in sailboats. Material is one. Material used for sailboat keels range from lead (the heaviest), to steel, to concrete to water (the lightest). The lower the ballast the stiffer potential the boat and if lead is used, that is better than water ballasted boats (which tend to be more tender). Water is more tender for a few reasons. First of all, it is located inside the hull in a tank and not below the boat. To compensate this often the manufacturer will have a shorter mast where the combined center of effort of the sails are lower, which also helps kill the sailing performance of the vessel as higher aspect ratio rigs are usually more efficient. But back to configuration.......if you have a shoal keel, which is essential in skinny water areas, to maintain a sufficient stability factor, you have to use more lead or steel or cast iron simply because the weight is not lower below the boat, but higher and so that additional lead has to be placed in a more fore and aft configuration while a racing boat, just for comparison reasons, can have a thinner, lighter keel that extends lower and hence the result is more stability, less wetted surface, which enables a higher aspect ration rig which helps performance. And, often boat builders will offer shoal keels for those needed them as an option, for more money as an upgrade from the standard deep keel. The more money is because more material is required for one thing.
I prefer the one that allows me to port tack the fleet while others play bumper boats at the start.
AS a senior citizen with over 50 years exp I prefer a fin keel, less wetted surface better pointing ability
Im a deep water sailor but if you are sailing in shoal areas like FL, barnegat bay you will have to make other choices
Im a deep water sailor but if you are sailing in shoal areas like FL, barnegat bay you will have to make other choices
Not necessarily in all conditions. Initial stability has more to do with the profile of the hull, and the total weight, rather than were that weight is located. Once the boat is well healed, then the location of the weight makes that significant difference.
Well...he said 'stiffer'.
And stiffer usually means a boat's ability to resist heeling forces in while sailing upwind in breeze. And that's way past initial stability, which you point out is mostly a function of hull form.
For stiffness you best have a deep fin keel with as much mass down low to lower the VCG and create a big righting arm.
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