JB, I needed to replace quite a few switches on my boat when I got her. If you remove the switches you will find the amp rating on the side 10a, 15a, 20a, etc as well as the part number. I called POCO sales for replacements. Google them and it will list their phone number in California. Their switches usually run around 10 bucks each. Good luck.

I can recommend pocosales as well, they are very good.

I like the look of toggle switches, and I always get switches to MIL-S-3950, which is the military spec for general high-reliability use. I have been using them for years and cannot recall ever having to replace one. A 15A on-off toggle is about $15 industrially, could be anything as surplus.

You can get them at alliedelec.com or newark.com. Skycraftsurplus.com in Orlando has mil switches, but they do not list them on their site, you have to call. Another good surplus place is https://www.surpluscenter.com, I always try them to see if they have something I can use.

I use 15A or 20A rated switches for everything, smaller switches are the same money. I like the screw terminals, since it is a lot of trouble to replace a soldered switch, unless it is part of a panel that can be removed and taken below for work. I use a spring-return toggle for a horn, but many folks prefer a pushbutton. In any event, don't put anything on the flybridge unless it is waterproof. Don't trust those little rubber boots, they only protect the top of the switch anyway.

Good advice from Peter.

The M DC distribution is all supposed to come from the Marinette Control Panel, which on my '75 boat is above the lower steering station (eyebrow panel). These 18 switches should all be 20A or less breaker/switches. You can replace them with 20A snapak breakers, which are magnetic although not waterproof. I replaced all of mine, they were original and one was failing every couple of weeks. I used breakers with metal toggle handles, but the snapak line is very good value. Got mine from Pocosales.com.

The switches downriver from these breakers, which should be everything else in the boat, can be ordinary toggles. It is inconvenient to have to look all over for the breaker, they are best kept in one panel. Many loads, such as radios, require a fuse or breaker just for the device. I like to keep these special fuses right at the load (radio) so that I don't have to hunt around to get it working again.

You should have a panel of 50 to 80A breakers for the main DC power. One feeds the left half of the control panel, one feeds the right half of the control panel, one feeds the anchor winch, one feeds the head, and so on. At least, that's the way I did it. I can post some wiring diagrams that I used if that might help...