A group of schoolkids on a field trip noticed something strange when swimming at Martha’s Vineyard, an island near Cape Cod, Massachusetts popular with vacationers.

With summer in full swing, the National Fire Protection Association (NFPA) and Electrical Safety Foundation International (ESFI) are joining forces to remind boaters, marina operators and swimmers to be aware of the potential electrical hazards that exist on board boats and in the waters surrounding boats, marinas and launch ramps.

Boating season is underway, with thousands of people taking to the water for fun and fishing. When it comes to boating-related hazards, sunburns and drowning come to mind, but Electrical Safety Foundation International says boaters should also be mindful of electrical dangers.