With New Zealand's marlin fishery so accessible, each season sees more and more guys and girls heading out wide in aluminium trailer boats to chase marlin. Not a cheap exercise by the time you've fitted your boat with the right gear to prepare yourself and your crew for that fish of a lifetime experience. Unfortunately, with each season that passes, many fail to raise a fish. Instead, their time on the water was spent burning through hundreds of dollars in fuel and left feeling somewhat disheartened, while others boast of their game raising success.
There are many reasons for fruitless days, even for the most experienced crews. However, one of the possible causes that seem to be surfacing is electrical current leaks and the negative effect this can have on raising fish to your newly fitted-out fishing machine. The stray current caused by an incorrectly installed electrical component, bad earth, or chafed wire uses the hull as a ground, turning your boat into a massive battery, the saltwater becoming the electrolyte. If left unchecked, any such electrical fault can be costly, as your aluminium hull combined with an electrical current and saltwater as the electrolyte will cause corrosion.
Even a tiny amount of current leak may result in fish only approaching your riggers or shotgun lures, not wanting to come close to the corner lures positioned close off your transom where the current is more noticeable. It may be that every bite seems to be half-hearted or 'soft' as the fish is distracted by the electrical current when approaching your lures, or it may be so excessive that even when you run over a fish, it lights up, paying no attention to your lures as its tails off in the opposite direction. If you're experiencing any such signs, it may be worth getting some electric checks done, even for peace of mind, as even mild Electrolysis will lead to some corrosion or bubbling of any paint finish.
Finding the leak
An electrical professional will test for current leakage using the proper meter, though tracing the cause of the leak can be time-consuming if detected. With every light, fish finder, chart plotter or elaborate electric gadget and a switch panel that resembles the Battlestar Galactica, the risk of current leakage from a stray connection increases, and where electrical cables are running through roughly-drilled aluminium bulkheads, exposed wires from chafing may be the apparent cause, testing each switch circuit one by one, will help identify any circuit at fault.
GRP boats are not immune to this issue, though more often caused by inadequate or faulty bonding between metal thru-hull fittings, propeller shafts and any other metal component that come into contact with the sea. Watch Marlin Magazine Vision of Granders, Capt. Chris Donato shares a day of boat maintenance, checking earth-bondings after experiencing several days of unusual bites.
The information in this article is to share a possible cause of too many 'no fish' days that may be due to an electrical leak. An experienced electrician should carry out any diagnosis.
NZ Marine Electricians - Since writing this article in 2020, I've had countless people tell of the huge improvement a leak detection and fix made to their fish raising success last season.
Please feel free to email any recommended Marine Electricians I share on this blog.Tauranga NZ - Jeff Scott Electrical 0277332452