Pentax Marine Binoculars
The 7x50 Marine has an internal compass that uses LED illumination, the most battery-efficient of all, to display its readings. There's also a rangefinding reticle scale, which aids your estimations of the distances of other boats (when their approximate height is already known). The 7x50 Marine is meant for use on water, built to withstand the elements and protected by Pentax's fine "Worry Free" warranty in any case.