[large snip, very informative] > because they are wide and stable that it is the beam that makes them > seaworthy when in fact they are only safe when equipped with large amounts > of ballast - something sea kayaks rarely have. without the ballast they are > potentially dangerous just a I was trying to point out in my discussion of > sponsons. > [ another snip, we all know that Tim has a metal block ] > > Cheers, > John Winters > Redwing Designs > Specialists in Human Powered Watercraft > http://home.ican.net/~735769/ A while back when we were discussing the design of a self righting kayak for disabled people someone came with the idea of using a water ballast, but then the problem was that as soon as the ballast cylinder hit the water it would fail to exert the vertical force required to complete the last 90 degrees of the recovery. I assume that the form of the life rafts is such that it is very unstable when sitting on its side, and the water in the pockets would right it up before it drains out. In the case of a kayak with water pockets, it would probably like to rest on its side without righting up. Therefore lead ballast (or CB Rocks) seem to be the only useful type of ballast for sea kayaks. As a side note, Derek Hutchinson shows a picture of a canister attached to the inner surface of the keel of a kayak designed to hold ballast. See? Even Derek Hutchinson sponsors Canadian Ballast Rocks, Inc.! :-) The last issue of Sea Kayaker talks has an evaluation of a life saving raft. They still do not get the clue. If the sea is rough, the victim would not be able to stay on the raft. A more useful thing would be a raft with the shape of an envelope. The paddler would get in and stay there surrounded by pockets of air that would keep him/her warm. We could call it "rescue capsule". It is good that at least a few of us are interested in safety issues for advanced paddlers. Probably 99% of the paddlers that buy their kayaks at REI do not even have the concept. - Julio *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Fri Mar 06 1998 - 17:13:17 PST
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