Yes, an hour meter can be installed on any boat, many have installed them on theirs. Connect to purple wire on tachometer, this wire goes hot when ignition system is on. The black is the ground.
IMO, this circuit is not intended for heavy loads such as a stereo or other power accessories which usually should have their own dedicated power feed, but there's plenty of capability for an hour meter in the gauge power circuit. You can also connect the hour meter back light to this purple wire if you want.