ABYC is the American Boating and Yachting Council, the organization that establishes construction and safety standards for all boats within the US (electrical, propane, lightning, refrigeration, etc. They do testing and make recommendations. Kind of like Underwriters Laboratory (ULL.
I am not sure where you can find a copy of their electrical standards. You might ask your yard or a marine electrician and see if they will let you read the standards.
I highly recommend you follow the standards. There are things in there that us untrained folks would never think about, but which could cause a real fire and shock hazard. To ease your mind most of the standards are fairly easy to follow and don''t cost big bucks.