Making your engine blue water ready
I was interviewing candidates for my next big trip from New Orleans to Panama this May 2016. (I will elaborate more on my reasons for taking the Slow Boat to Panama in upcoming newsletter.) A potential crew member that I ultimately invited mentioned that he crewed on a boat bound for the Galapagos from Panama City when the engine was ruined by salt water coming up the exhaust. I e-mailed the skipper and owner of the boat, and he said that tacking back to Panama City with a ruined engine was the hardest thing he had ever done. Unfortunately, this happens regularly to sailboats that attempt their first big ocean crossing.
The dean of sailboat repair and the author of the diesel engine bible for sailboat owners Nigel Calder writes on page 254 of Marine Diesel Engines, 3rd Edition, 2007:
“Every year I get a number of e-mails from people with flooded engines, mostly sailboats. More often than not the engine has functioned fine for years, but then a long-dreamed of cruise was undertaken and at some point the engine flooded. The common thread is that on an offshore passage, the boat got in rougher conditions or bigger seas than it had seen before.”
There are three ways that salt water can stuff your engine. It can foul the fuel tank through the tank vent, it can back flow through the exhaust, or it can siphon through the salt water cooling intake. We have had lots of water contamination problems on our outboards, and dealt with water in the gas tank on our previous boat. Thus, this became a top priority on our outfitting for the big trip in 2016. On the Slow Boat, we moved the vent from the side of the boat to high on the cockpit coamings, and put in a water alarm on our new, easy-to-change Racor diesel filter. Also, since we got back from the Bahamas, we installed a new exhaust outlet with a flapper valve to retard water back filling. Also we installed the gooseneck pictured below which should make siphoning more difficult:
That leaves us to deal with the potential of salt water siphoning from the engine salt water intake and flooding the engine. Closing the engine seacock while the engine is not in use is one alternative, but our boat shares a seacock with the head for flushing with salt water. Thus, we will probably look to install a vented loop between the salt water pump and the heat exchanger before we set off.
Replacing an engine on a small Pacific island, is a huge expense and headache that any boat owner will want to avoid. None of these preventive measure is 100 percent effective, but they increase the odds that your first ocean crossing is not your last.