I take a separate compass as part of our navigation equipment--a nice brunton.

The watch is a Casio Pathfinder 3143. Solar powered, so it needs no attention. The Altimeter works quite well, if you understand how it functions. It does not read out every time your elevation changes. It gives a new reading about every five minutes. As I drive to the mountains in the car, it is always a bit behind the elevation signs on the highway for that reason. On the trail, that's less of an issue.

I reset/recalibrate the elevation every morning on the trail, so that at least any change in weather overnight is accounted for. And any change in elevation overnight would obviously indicate a change in barometric pressure.

Not sure why you would need an altimeter on a lake. And the compass on this watch is silly--only given rough indications of direction, rather than the kind of precision you need to navigate. Then again, I learned navigation on a sailboat, so I take compass precision seriously.