Standard Horizon makes a couple of models (HX850S and HX851) which do all (or just about all) of the above.
The alkeline battery pack doresn't come with the unit and has to be purchased separately.

The HX851 isn't small, but it is quite light. Floatables have to be.

The #s for GPS coordinates are very small and I wouldn't want to deal with this on a day-to-day basis for
navigation.

I recently bought the older model new for about $150 with the idea that it would not only serve as a back-up
handheld but would also go in the grab bag. My understanding is that the only difference between the older
model and the newer one is that the latter allows for waypoints and is somewhat easier to use for
navigation.

Jerry