Carraig nan Ron (seal rock) is a navigational hazard to both the warships and civilian ships that ply Loch Long. It lies off the point which separates Loch Long from Loch Goil. The light beacon is operated by a solar panel. In the distance is the Royal Naval Armament Depot at Coulport. Unlike Glenmallan, which services surface warships, Coulport is specifically designed to service submarines