SEPTEMBER 2017 BEACON

Marina Drowning Warning

By Ron Draper

Now for a topic near and dear to me, albeit no joking matter. Since people started putting shore power on boats there has been an added electrocution, or shock hazard due to the surrounding water. Much lesser known however, is the added danger of drowning. For many years, every now and again, someone would turn up drown in a marina. Most times it was determined to be a person who drank too much, jumped or fell into the water and drown, no reason to look any further. Then back in 1989 or 90 or so in a marina in Ohio a healthy teenage boy jumped in behind his I/O powered boat and didn’t come up. His buddy jumped in to get him and he didn’t come up. A 3 rd boy jumped in to help and all 3 drowned. They were young, healthy, not drinking, and known to be good strong swimmers. There was no immediate explanation, and an investigation ensued. Electrical engineers from the ABYC and others were called. I was working as a marine electrician at the time, a member of the ABYC, and also teaching the Marine Electronics course for the United States Power Squadron. I became aware of all this because I was protesting vociferously to the USPS about their policy of teaching people to cut the green (safety ground) wire at the shore power inlet to their boats. It was actually a test question, and if you chose the answer to leave it intact you got it marked wrong! This had been their policy for years because it was a good way to prevent galvanic and electrolytic corrosion of the underwater metal parts on boats, particularly in salt water. That’s a whole ‘nother topic and I may expand on it in a later article. It turned out that a faulty battery charger was leaking a very small amount of AC current through to the DC side of the electric system, that in turn, followed the DC ground out through the outdrive and through the water to the metal dock pilings and seawall on its way back to the ground rod at the service entry (shoreside breaker box). When the boys jumped off the back of the boat, they jumped right into the stray current field. Here’s the confusing part, the boys were Not electrocuted, or shocked, the autopsies revealed no evidence of electrocution, they simply drowned.