how do YOU make a waterproof on/off switch

[Larry Kuntz]

Like Crazy Ivan and Big

Like Crazy Ivan and Big Dave said, I use both of their methods. I use a miniature double pole switch (the good brands are rated for 5 amps) and a rubber boot. I wipe a little silicone (RTV) sealant around the threads as I tighten the boot/nut for the switch. This switch shuts off ALL power from the battery.

[himszy]

On my Darnell T Class,

On my Darnell T Class, there's two through-hull thumbscrews with a piece of (what I believe to be) copper shorting them. To turn off, you loosen the screws slightly and lift the copper piece up.

A hole in the copper ensures it stays connected to the hull so you don't lose it.

Michael