Complex sentence: Boats with internal combustion engines are prohibited in the interior lagoons, except for Grave Yard Pond, where a concession rents motor and pontoon boats, canoes, and kayaks for recreational use.
Split into simpler sentences: Boats with internal combustion engines are prohibited in the interior lagoons, except for Grave Yard Pond which is the location of the boat rental concession. This rents motor and pontoon boats, as well as canoes and kayaks for recreational use.