Ulli Hoeger asked about skeg materials and I thought I'd add my two cents worth to give everyone something to think about: I would not use aluminum in a skeg and would not have aluminum in the water as either a skeg or a rudder on any kayak because there is some evidence it attracts sharks. It is a well know fact that AL in sea water under goes a slow chemical reduction called electrolysis, it breaks down the molecules on the surface and discharges a weak electric current in the water. It has been suspected by researchers that this current is mistaken by the sensing organs on a shark as an injured fish thrashing in the water. There also have been a number of antidotal reports that support this idea because sharks have attacked boat props, rudders, etc. including one scary story of a sea kayaker I think in the Deep Trouble book who had an aluminum skeg on his kayak. I personally do not prefer a rudder but if you regularly paddle in known shark waters I would replace any aluminum rudders or skegs, or at the very least put several coats of a tough paint on it. I would think for an all wood S&G kayak a wood skeg would be plenty strong, especially if you put a layer of fiberglass over it. Peter *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced/forwarded outside PaddleWise without author's permission Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
"Peter A. Chopelas" wrote: } Subject: [Paddlewise] skeg plans > Ulli Hoeger asked about skeg materials and I thought I'd add my two cents > worth to give everyone something to think about: > > I would not use aluminum in a skeg and would not have aluminum in the water > as either a skeg or a rudder on any kayak because there is some evidence it > attracts sharks. It is a well know fact that AL in sea water under goes a > slow chemical reduction called electrolysis, it breaks down the molecules > on the surface and discharges a weak electric current in the water. It has > been suspected by researchers that this current is mistaken by the sensing > organs on a shark as an injured fish thrashing in the water. There also > have been a number of antidotal reports that support this idea because > sharks have attacked boat props, rudders, etc. including one scary story of > a sea kayaker I think in the Deep Trouble book who had an aluminum skeg on > his kayak. This is very weak "evidence" - this sounds like an untested hypothesis. C'mon, this is as bad as the old "aluminum pots cause Alzheimers" idea - it's ridiculous to worry about all the untested or poorly tested ideas that come up. (FYI, for those who don't remember :-), the aluminum & Alzheimers connection was made by some researchers who thought they found more aluminum in the brains of Alzheimers victims than in other people. As it turned out, this study was not repeatable. But even if it had been, the idea that eating out of aluminum pots causes aluminum to acculumate in the brain was *highly* speculative, and completely untested by this study. Yet I know of many people who threw away their aluminum pots in fear.) For a contrary speculative hypothesis, how about the idea that many predatory fish will strike at shiny objects? That might well account for the "antidotal" (anecdotal) strikes at props, rudders, etc. Personally, I think this one is far better supported than the Al electrolysis idea, but helps to show just how useless this speculation is as a guide to action - until someone tests it, it's just nothing more than a speculative idea. *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced/forwarded outside PaddleWise without author's permission Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Bob Myers wrote: > > "Peter A. Chopelas" wrote: > } Subject: [Paddlewise] skeg plans > > Ulli Hoeger asked about skeg materials and I thought I'd add my two cents > > worth to give everyone something to think about: > > > > I would not use aluminum in a skeg and would not have aluminum in the water > > as either a skeg or a rudder on any kayak because there is some evidence it > > attracts sharks. [snip] > This is very weak "evidence" - this sounds like an untested > hypothesis. > > C'mon, this is as bad as the old "aluminum pots cause Alzheimers" > idea - it's ridiculous to worry about all the untested or poorly > tested ideas that come up.[snip] > For a contrary speculative hypothesis, how about the idea that many > predatory fish will strike at shiny objects? That might well account > for the "antidotal" (anecdotal) strikes at props, rudders, etc. > Personally, I think this one is far better supported than the Al > electrolysis idea, but helps to show just how useless this speculation > is as a guide to action - until someone tests it, it's just > nothing more than a speculative idea. Bob, you're just an old curmudgeon <g> ... clearly the idea that aluminum skegs attract sharks has a useful function: folks who make money replacing skegs would love to foster this idea. (I don't think Peter replaces skegs, so that's not his motivation.) BTW, up here, sharks seem to like to bite the body of surfboards -- maybe they're attracted to polyester resin ... better coat that kayak with epoxy! <more grinning> -- Dave Kruger Astoria, OR older, and more curmudgeonly! *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced/forwarded outside PaddleWise without author's permission Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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