I was at a medical conference in Maui a few years ago, and this topic was discussed at length, along with other environmental dangers. It was believed by most of the medical gurus there that if you are allergic to bees, wasps, or hornets, or one of those types of creatures, you have a very high risk of being allergic to any jelly fish sting, the more potent the sting, the higher your risk of an anaphalactic reaction. It is in EVERYONE's best interest to make sure you carry benadryl along with the vinegar, and if you use an epi pen for insect stings, you should carry one with your stuff if you are diving or snorkeling, just in case. I carry mine, especially when traveling.