Could you post a picture of the switches you have questions about? That would help.
Your boat is 27 years old, previous owners may have changed some connections. Have you tried turning the switches on, one by one?
I'm sure some members here can help you.
For switches we can't figure out, we can always look at the color of wires on the back of the switches to determine the systems they are connected to.
2006 Bayliner BR205
A1 Gen 2 1.47
5.0 carb engine