The dreaded Sea Lice, little critters(actually Jelly Fish Larvae I think). They make you itch till raw. We use a product applied like sunscreen at wet suit openings as this is where they seem to get you. Then after diving a little mist with my famous oil and vinager, a few croutans and we have a salad. When all done a fresh water shower on the boat with soap, dive buddies are encouraged to help each other with this part.