Duck Island Ridges These are two narrow rocky ridges running from Duck Island (one of the Isles of Shoals) toward Boon Island. reaching within I mile of the latter. Depths are from 25 to 30 fathoms. These are good cusk and haddock grounds in the winter and spring, the cusk remaining on the ground also from April to October. This is a cod ground in winter and spring, the fish being taken on the "bobber trawl" which is a trawl of the ordinary type buoyed to "set" 1 fathom or so from the bottom. It is a hand-line ground in summer for cod and pollock. Both small boats and vessels, line trawlers, and gillnetters operate here. It is also a lobster ground.