Caribbean itch: eight cases and one who didn't (Exercise Blue Calypso Diamond).

Stinging plankton are a potential source of irritation and morbidity for those pursuing aquatic sports in areas where they are numerous. The problem is seasonal, and likely to be familiar to local people. We describe an incident in which a number of military personnel were affected by the stings of the thimble jelly fish (Linuche unguiculata), with a brief review of the biology of the problem and some recommendations for prevention.