Boat full-'o'-clowns.
Thinking they're
so cool/sexy/badass/whatever, but too blank upstairs to consider what they're doing (going very, very fast) ... and to then take even
sorta precautions. Like, oh, SITTING DOWN. With belts on. And perhaps wearing lifejackets.
More than likely a few too many brewskis and macho bravado. And the broads are just broads; they don't know shit.
Watching the full video is a six-minute escalation of hilarity.