Unlike a gas boat, running out of power on an Arc One is highly unlikely. Not only will the boat give you a warning if you start to get low on battery, but it can also run at slower speeds for extended periods of time — think of low power mode on your iPhone. If you're in the middle of Lake Tahoe, you can get back to any other point on the lake with less than 5% of power.
If you do manage to run out of power, you can get towed back to the nearest dock. Unlike with gas boats which need an actual gas pump, any dock with a plug will do the trick.