Were you wearing an exposure suit ? Sea Wasp or MOW would probably not penetrate neoprene through to sting you in the belly. If it were a MOW you would probably see it either before or after unless it is a piece of broken off tentacle.
Stonefish or cone would probably get you in near convulsions very quicky. My guess would be some nasty species of sea urchins. The spines can easily penetrate neoprene but then you should be able to see the broken off tips embedded under the skin.
I have been stung by MoW across the neck, sea urchins several times , crown of thorns , and fire coral. the fire coral sting is nasty. The wound festered and took months to heal.
Stonefish or cone would probably get you in near convulsions very quicky. My guess would be some nasty species of sea urchins. The spines can easily penetrate neoprene but then you should be able to see the broken off tips embedded under the skin.
I have been stung by MoW across the neck, sea urchins several times , crown of thorns , and fire coral. the fire coral sting is nasty. The wound festered and took months to heal.