Capsizing

[salmon]

Dear All:

Is it possible for a U-20 to capsize and if so, can anything be done to prevent a complete "turtling"?  I'd like to purchase one of these boats used and use it for day sailing without a spinnaker, but want to be sure that if I'm in open water where there's a good breeze, the keel will be adequate to the task.

Any advice would be appreciated!  Many thanks!

Mike
(reply to: salmon@fau.edu)

[Orin]

I just had mine out in about 20 knots with my wife and a teenager with no sailing experience. There was about was about an 85 mile fetch for the waves to build but it was quite choppy. A little unpleasant during that small stretch of sailing, my wife was steering (practically no experience) and we broached a couple of times as she panicked at the helm. At the end of the day it was still great to get out and see dolphins and the likes. In any case, we were no where near capsizing in those conditions with full main and jib. The boat stayed surprising dry, only a couple of waves managed to get us wet, and we had one wave get a little bit of the cockpit floor wet when we turned down wind.

In my limited experience I'd say it would be extremely difficult to capsize one of these boats. Probably impossible with wind alone. I don't think you'd want to be out in those conditions anyway, as there would be little enjoyment there IMO.

In a sea state that would cause you to capsize I think there's a good chance the next really big wave would right the boat.

A general rule of with boats is that it takes a cresting wave abeam 1/3rd in height of the length of the boat to capsize it, and because they are less stable inverted a much smaller wave to right the boat. (Eg a 6'11" tall wave for the 20'10" U-20)

Perhaps someone with a bit more experience could weigh in, but these boats are fairly stable. Perhaps not the easiest choice for single handing, but I've single handed much harder boats to sail.

[Mark Allen]

I have been blown over in 50 knots and the boat just bobs on its side. Once the wind drops the boat will come back up. It has 450 pounds in the keel and should be enough to right the boat. I always caution people to not go out on the keel to right the boat in a broach because the boat is so wide the chances of you getting washed off the keel and ending up in the water are too high. Better to just stay in the boat.

To answer your question the only risk is if the keel is not secured properly. If the keel boats are loose or damaged and the keel retracts into the boat if it is knocked over past 90 degrees the boat could turtle. I have only heard of this happening once in San Francisco bay. Checking the bolts and keeping the keel box in good condition should prevent any risk of the keel retracting and possibly turtling the boat.

Other than that the keel is up to the task and should always allow the boat to self right.

Mark

[Bob Abelin]

There is a video of a capsized U20 in San Francisco Bay. You can search for it on YouTube.  It’s pretty clear from the video that the keel is at least partly retracted so it either wasn’t secured or something on the keel box failed.  I’ve definitely had the boat on it’s side a few time but it has always righted itself fairly easily once the sheets were released. 

[U20CarpeDiem]

We’ve been sailing in Lake Michigan.  When winds are blowing uncomfortably and seas build, we reef the main.  The boat sails nicely under control with no loss in point.  Rig your jiffy reef just in case.

[David Krausz]

From my understanding, there were two issues with the capsizing in San Francisco. First was there were continuous spinnaker sheets which were too short to allow the spinnaker sheet to completely depower. That meant that the boat could not recover from a knock-down. The mast began filling with water.   Second was that the keelbolts broke, causing the keel to retract.    U20s have only 2 keelbolts.   Many, including mine, have been retrofitted with 4 keelbolts to prevent such a failure.    I've been knocked down in big breeze and big chop many times and have never felt in danger of capsizing.  I think if your keelbolts failed on a knockdown, you would absolutely turtle the boat.