A strange thing is happening this year. Several of the new people that have never been to Nome before, and have never stuck their head under water before, are showing up with electric air compressors. Luckily these do seem to be rated for breathing gas, and are suitable for diving. The problem is that they have no good way to power the compressor. They have a standard 12V marine starting battery, but the stock alternators on their dredge pumps are not enough to keep up with the demand of the electric motor. Thus they end up with no air and a dead battery. several people tried to modify their engines to have larger alternator or generator, sometimes belt-driven. Others buy extra batteries, at super-expensive Nome prices, and charge them up on shore. Others buy a Honda EU1000 and have that running all the time.
I don’t get this fad. There are very rare times when I want to run an air compressor without my dredge pump. Most of the situations are when the dredge motor dies while the diver is under water, and needs enough air to get surface. This can be mitigated by simply having a larger air reserve tank. There is no air quality benefit to running electric, since the dredge pump had 5x to 10x the horsepower, proper air intake placement takes care of this.
Electric stuff in Nome does not last long, and must be well protected. Salt air is brutal, salt spray is worse, salt water immersion is worse yet.
I prefer to run one dredge pump engine, that belt drives my air compressor, goes to a 9 gallon reserve tank, and down to the diver. This way when the pump dies, I can feel it immediately while underwater and I know that I have only 2 minutes of air. There is one large fuel tank to keep track of, since the dredge pump is so loud, it is hard for the deckhand to hear if a gas-powered air compressor cuts out because it’s fuel tank is so small, and hard to safely fill while running.