Cove of Jeffreys (West) A small shoal in the western part of the Cove of Jeffreys, having 50 fathoms over a bottom of blue clay and rocks and rising from the 60 and 70 fathom soundings about it, is about 1 ½ miles long by about 3/4 mile wide. This shoal is SSE. from Boon Island 15 miles. It is a winter ground for cod and haddock.