Sail away to Catalina! Isthmus Cove, Two Harbors or “The Isthmus” is located on the northeast side of Catalina Island, just across the geographical isthmus from Cat Harbor. This cove is large and contains 249 moorings and anchorage for over 100. Even so, remember that the moorings fill up fast on the busy summer weekends! The Isthmus is a major center of boating activity on the Island. Shore boat service is available by radio if you don’t want to use your dinghy. If this is your first time to The Isthmus, check your chart for the location of Harbor Reef, a local hazard located at the north end of the cove.