Overflowing kayatank

[dgax65]

I wouldn't expect a fire in the potted timer switch or a fishfinder. The electrical system should be fused to protect your kayak in the event of a short circuit. A dead short between positive and negative wires would cause a catastrophic failure of the battery. Before the battery is destroyed (seconds), enough heat will be generated in the affected wires and the battery itself to melt a hole in your kayak. You probably won't have a fire, because the water filling your kayak will put it out.

That is a worse case scenario. The chances of a dead short are slim.

More likely is a situation where you have corrosion or mechanical wear on wires that breaks down the insulation and results in arcing and overheating the wires. It may not be the flash-bang that you would get with a dead short, but it could definitely create enough heat to melt the PE hull or ignite the insulation. PE has a relatively low melting point. If your wiring is in contact with the bottom or sides of the hull you could melt through and start taking on water.

The basic 12vDC 7A-hr battery that it used on most kayaks has more than enough energy to cause catastrophic damage to a kayak. The use of a properly rated fuse on the positive lead close to the battery will nearly eliminate the possibility of such an accident.

The in-line waterproof fuse holders for the standard AGC fuses don't hold up well in kayaks. The cheap metal fuse clips will rust easily and they really aren't very waterproof. Its better to use the ATC (automotive blade-type) fuse and waterproof holder.


ATC on the top. AGC below.

A little silicone grease around the cap of the ATC fuse holder will keep it waterproof. A small amount of dielectric grease on the blades will prevent corrosion.

I would not recommend using circuit breakers on a kayak. A circuit breaker is just a spring-loaded switch with an automatic trip. They are very susceptible to corrosion as is any switch. Using a mechanical trip in an environment that is conducive to corrosion is just not a good practice. Fuses have no moving parts that can stop working if rusted. Go with a fuse.

Batteries should be kept in waterproof bags or boxes.

Fishfinders and GPS units are fused to protect their delicate circuitry from voltage transients. This is more of an issue with motor driven alternators. You won't get many transients on a battery powered electrical system. The starting surge for the bait tank pump will cause small fluctuations in voltage. I've seen 0.2vDC transients in bus voltage as my Kayatank 500gph pump cycles. That's isn't going to hurt your FF. A shorted/corroded connector plug is a more likely cause of failure of your FF. Having a properly sized fuse on the FF power cord might prevent damage to the unit in this situation.