Yes ... I for one do not want to get stopped (or even worse rear ended etc
.... not that likely but ... ) on the way back home at night because of a
failed tail light/stop light/turn signal. Yeah, I know ... check all lights
before you get going, and always carry spare bulbs, ...

Heard from some that you should disconnect
the tailer lights before putting your trailer in the
water. I can't see why you'd do that. Are they
worried about a hot bulbs shattering when hitting
the cold water ?