I'm sceptical that the mirage drive would be more likely to attract a shark attack than a paddle kayak.
This comes from Wiki:
'Sharks are equipped with sensory organs that detect the electricity generated by muscle movement called the Ampullae of Lorenzini;
.....another theory for the low fatality rate of shark bites is that the electrical receptors, which pick up movement, do not pick up the same signals from a human as they do a wounded seal (which creates a disturbance in the water similar to a human swimming), and so they are more cautious.'
So it seems sharks are attracted by the electrical impulses emitted when muscles contract and that sharks can differentiate between the impulses from their usual prey and those of something unfamiliar to them.
A mirage drive would emit no such impulses as far as I am aware. Sure the movement mimics a penguin flipper but are sharks attracted by sight? If that was the case I'm sure we'd be hearing of more attacks on Hobies. In the AKFF forum there was some discussion on mirage drive pressure waves being attractive to sharks but a paddle would also exert a pressure wave and without proper research I don't think you can conclude that a mirage drive is a shark magnet.
As far as I am aware Hobie's aren't overly represented in kayak attacks. All types of kayaks are prone to an attack. Remember though a kayak attack is an extremely rare event and an actual attack on a kayaker thrown into the water even rarer:
http://www.sharkresearchcommittee.com/u ... ayaker.htm
PS - Geoff I could be wrong but I thought it was an Adventure that the kayaker was thrown from and not an AI??