I've had various issues with Maglites, and while typically taking them apart and tweaking them a bit (typically involving sandpaper) will get them going again, this has happened far to often to select them for a critical need. I think a lot of this may be from the aluminum (inside) and springs oxidizing. Perhaps this is more of an issue here in the Pacific Northwest (cool, moist air), but on the water (esp. salt water) is going to be a tough environment. I also think their waterproofing is hit or miss.

All in all, why take the chance. I'd take a UK 2L over a mini-mag in this environment any day and the 2L will take a LOT more abuse and a LOT more water.

-john

Edit: I don't have one, but the Tekna Splash-Lite LS looks like a great water safe backup light.