http://www.cbc.ca/world/story/2007/04/15/sea-lion.html

The message board kept giving a 'possible spam' on the url every way I tried to post it. Dunno how it could have mistaken a 13 year old girl in Oz for Kus here, who all sea lions share a hatred for....

Well, it must be my girlish figure I think there is a good chance that these events are highly under-reported. Usually there's just a bump or nip, nothing major, right? In this case the girl was hospitalized so a bigger deal.

Their estimate of weight is a bit low, suppose depending on species there but I note "males up to 8-13 feet in length and 500-1800 lbs. for the stellars.
"the males establish territories and assemble harems, usually numbering 10 to 15 females" "Males are physiologically able to breed at 3 to 6 years, but they probably do not participate until after 8 to 10 years because of strong territorial competition among the largest males"

Given these scenarios (and the one in Seattle & Cal) I think it's safe to say they are either acting on asserting their territory or....wait for it..... it's the noise that pisses them off. I can just see the speedboat with a group of hollering, yippying group cruising past the...pod?

Just a theory without much scientific background but next time I be wary wary quiet when gliding next to these guys (and not swear my head off at them )