Can I hear a big AMEN! I personally think that the shape of a kickboat with pontoons probably helped as it's silhoette(sp?) can't be confused with a seal. A round tube might have been toast or should I say sushi.
I figure if the scientists say surfers are hit because they're mistaken for seals swimming, a round tube has to look like a seal spy hopping, and therefore an even easier target of opportunity. JMHO It's also only slightly comforting to think that out of the less than a 1,000 recorded California shark attacks, no one has been confirmed to actually have been eaten. In Australia I read that there was one case of a full-on eating, but it was by a emaciated, Drift-net entangled, Great White. Damned Drift-netters. Every other confirmed eating world wide that I have heard about or read either involve already dead people, or some other extenuating circumstance such as chumming, etc.

Tight Lines,
Wade