Duck Island - Portsmouth, New Hampshire

Harbor seals congregate off Isle Shoals from June through August, and love to cause mischief with visiting divers. The site— which ranges from 70 to 80 feet and features terrain from rock outcroppings to beds of sea grass — is also rich with striped bass, starfish, scallops, wolf fish, haddock and cod. Local Dive Guide: Cold Water, Beginner Dives, Big Animals, Guide Needed, Summer Trip