Welcome to Occoquan Harbour Marina! The perfect place to keep your boat on the Potomac River. We are located on the Occoquan River, 3.7 miles from the Potomac River. Our boat slips on the Potomac River offer deep water 9' average at low tide. Transient Slips on the Potomac River are welcome too! Our boat slips are near Washington DC. You will enjoy floating docks, lift slips, BBQ Grills, Slip Holder Pavilion and much more. We are a full service marina; which means we can perform boat repairs, haul outs, fiberglass repair, boat prop repair, boat engine repairs and winterization services.