Attacks on boats

Great white sharks infrequently attack and sometimes even sink boats. Only 5 of the 108 authenticated unprovoked shark attacks reported from the Pacific Coast during the Twentieth Century involved kayakers.^[30] In a few cases they have attacked boats up to 10 metres (33 ft) in length. They have bumped or knocked people overboard, usually 'attacking' the boat from the stern. In one case in 1936, a large shark leapt completely into the South African fishing boat Lucky Jim, knocking a crewman into the sea. Tricas and McCosker's underwater observations suggest that sharks are attracted to boats due to the electrical fields they generate.^[31]