We sailed a few years back in May and had 0 issues, and I'm a mosquito magnet. On land we had dinner one night at Pussers on Marina Cay and the mosquito's/sand fleas were absolutely horrendous. It became a running joke in the restaurant there were 3 cans of Off and everyone was passing them table to table. We all got a good laugh out of it and ended up meeting some nice people from Iowa!