Christi:Can you provide a reference to this? I'd be interested to read more about this. I've never seen them or heard of any reports of them here...I even spoke to to the local FISH ID guru.
The only link I've been able to find on that jelly (not closely related to the Australian box jelly) times out when I try to access it. I have personally seen Portuguese Man o' Wars (Men o' War?) in the channel between PdC and Cozumel.
EDIT: Widening my seach yielded some more links, but the only one (so far) that quoted a range was this one:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Carybdea_alata.html
and it only says "Jamaica; Kingston Harbor", but other sites report it as a problem in Hawaii.