Another boat was sunk this week off the West Australia coast by a whale & initial reports was that it was concrete (was actually wood, see link below).
I was having a discussion with a surveyor yesterday and he was telling me about the first Fremantle to Bali race back in the 70's where a whale came up between three yachts in company (two fibreglass and one concrete) and the whale starting rubbing himself under the hull of the concrete boat. Apparently the yacht lasted about three minutes before going down, the crew had just enough time to grab their wallets, camera and ditch bag. Apparently there is a very funny picture around which captured one of the crew marching off the yacht into the water with the whales' tail sticking up in the background.
The surveyor's theory is that the whale's sonar cannot detect the fibreglass yachts. However the concrete yacht looks like a rock so the whale came up for a scratch, unfortunately for the concrete yacht.
So what do you think? Any anti rock measures that concrete yacht owner's can take?
Men 'lucky to be alive' after whale sinks boat - ABC North West WA - Australian Broadcasting Corporation