We get a lot of questions here about jellyfish, the favorite season of that critters is during the trade winds of March - June. However we do not get many jellyfish and this would be a snorkeler's or diver's least concern. Your chances of getting a serious sting would be 1:5000 or more. A buddy has been diving here for 15 years and never had a serious sting! We have no 'deadly' jellyfish in the Caribbean - such as the box jellyfish.
By the end of November there are practically no stinging critters in the water due to the change of seasons and drop in water temperature.
Here is a list of the most common marine animales that can cause bite or sting injury.
Jellyfish (not all types sting)
Portuguese man of war (a type of jellyfish)
Stingray (not all rays have stingers)
Scorpion Fish
Stonefish
Catfish
Lionfish
Sea urchin
Sea anemone
Hydroid
Moray eel
Shark
Thimble Jellyfish
Electric eel
Coral - especially fire coral
Barracuda
Sea Lice
Common symptoms are: Pain, Stinging, Swelling, Redness, Numbness, Rash, Itching, and Open Wounds (as when you get bit)
We recommends that you follow up with a Doctor in these situations:
You have a sign of an infection (redness, swelling, pain, drainage, fever)
Uncontrolled bleeding
If you have not had a tetanus shot in 5 years
Any problem with the wound that bothers you should be reported to your doctor.
What can you do to prevent these?
Wear Water Shoes - we make everyone on our boat do this when we're out exploring the sandbars and islands. Protect your feet.
Don't run into the water or dive headfirst - OK, just use common sense with diving in, and don't run so fast you'll fall down onto sharp things.
If you don't know what it is -- DON'T TOUCH IT! The other part of this is to learn what things are, and what things sting and bite and which don't
Do not swim with open wounds
Don't wear bright shiny clothing, jewelry or equipment - this is primarily true in murky water of low visibility. On the reef in the daytime, where fish can see what you are, it's not as much of a problem but a little shiny lure hanging around your neck could still prompt a fish to go for it.
Don't hang your body parts over the side of a boat while chumming the water! . This is especially true at dusk and night. - and certainly don't swim while chumming!
Avoid swimming or hanging your body parts in the water during feeding times of dawn and dusk, and avoid night time swimming. (Snorkelers and Divers on reefs can of course enjoy the life after dark, but this is a bit different than just flailing around in the darkness anywhere).
Use the oily lotions before you get in the water to ward off stings from jellyfish
Push floating seaweed away from you - it might harbors sea jellyfish
