I must clarify as well...the jellies did not interfere with our time. Peter Island, on our trip, had the most(~20-30) when we were leaving and I needed to dive the mooring ball for the safety line. The prior night we saw gads of fish, stingrays, turtles but no jellies...

Use common sense and be aware...otherwise, they should not interfere with "Natures little Secret" and a fabulous experience.