iv'e worn an old 1mm(with a cheap lycra hood from divers direct) full suit the last 2 days freediving and had zero stings with moons everywhere(the full lycra body skin wasn't 100% effective but acceptable). in my view a .5-1mm full wetsuit(w/hood) is sufficent protection from moon jellyfish. in reguards to portuguese man of wars, well that's another story. as for thermal protection while diving the deeper sites(55-125FT) the past month, i've been using a 3mm hyperstretch with a 3/5 hooded vest, however, i chill easy and our dives are long as we have 100HP steels. the majority of my dive buddies have been wearing 3mm full suits(hoods/no hoods)or less the past few months. haven't encountered any thermoclines as noted further north of the keys,,, ,,,,,,
reefman
key largo