I remember at a Sydney beach, can't remember what one (not Bondi though) there was a whole bunch of Box Jellyfish lumped together. They had to block that whole area off, I can't for the life of me remember what beach since it was 5 or 6 years ago, I just remember being terrified of them. To be safe, Vinegar will be carried on the boat to pour on the stings until the person reaches the nearest hospital, though of course a First-Aid kit will be aboard with some anti-venom, but if the worse happens it good to have a plan in place. Like the day-long horse rides I go on, we gotta carry Eastern Brown snake anti-venom with us since they are very common in my own area. Never seen anyone get bitten, but better safe then sorry. Though they mostly leave people alone unless provoked.
I'm sure I'll be fine though, if I see something dangerous I'll leave it alone. After all I'm the one in their home. Might snap a quick picture then be on my way.
