So Larry, what would you recommend for this MOB application?

I have one of those plastic mounted magnetic switches used on windows in
burglar alarm set ups epoxied into the pole. The magnet is glued into a
Velcro strip with a line to the boat. When the MOB pole goes overboard, the
magnet stays behind and the light goes on. Perfect - except for reed
switches being unreliable.

What would be flush, watertight, and reliable?

--
Roger Long