[pbb]

As someone with a stats background (Ph.D. in Sociology with a quantitative focus, M.A. in Demography), I would agree that there is nothing here that suggests any conclusive "statistically significant" differences by propulsion method.

The OP is correct that you would really need to know how many people are out there in these types of kayaks at risk of getting attacked to do the analysis correctly.

In fact, you would ideally need to know not only what kind of kayaks are out there in consumers' hands, but how much they use them. In other words, if you had 1000 people with Hobie mirage kayaks and 1000 people with paddle kayaks, and the mirage drive kayakers spend twice as much time on the water as people with paddle kayaks, you would expect them to experience twice as the number of shark attacks even if the rate of shark attacks was exactly the same.