Also, there is an inverter in the boat the instructor says isn't wired correctly.
Inverter?
Inverter takes 12volts DC and outputs 110 AC. The higher end models double as a charger. That sounds unlikely with the size of the boat you have.
If it is a "converter", 110 AC down to 12 DC that does not belong on a boat!
Marine grade only 12volt chargers or inverters.
You put the wrong 110 appliance on your boat and you are likely to do a lot of damage to your boat and the others around it.
Same goes with incorrectly wired boats -
novices should not be wiring boats.I am the #2 person in a TowBoatUS marine assistance company in central Jersey.
We respond to 50 or so vessels a year that look like the one below. I have thousands of pictures like this.
It is usually the same - "I thought the batteries were charged" "I just checked it last month" etc.
The interesting thing about this picture, the boats belong to two professional captains.
The boat floating belongs to a real pro - probably the best tuna fisherman in the tri-state area.
The one sunk belongs to a "professional" bull chitter. He is a "pro" captain but he writes the fishing column for the NJ Star Ledger. Not much of a captain either.