Adults up to 5 feet, males and females same size, wide short muzzle nostrils forming a V (gray seals have longer snouts and nostrils form a W). Pelage (fur) patterns vary vastly from very dark with white spots, white with dark spots or plain white bellies. Between May and beginning of August, on the east coast of USA, seals molt their fur getting very dull and brownish. Pups are born in early May through early June and are weaned in 28 days or less. They can swim from birth.
Coastal waters and rivers. Will climb out (haul out) on rocks at low tide or even high tide, if the rocks stay above the tide, to rest and pup, often gathering in large groups. They feed at river mouths and along shore line catching fish as they come out on the ebbing tide, but also can be seen 20-30 miles offshore feeding. They usually feed alone but can be found feeding in larger groups herding schools of fish.
When in the water they are often curious and will approach boats, but on land seem to feel very vulnerable and will scare off the rocks if approached too closely.... it has been my experience that they are more afraid of canoes and kayaks than of lobster or motor boats (if not approached to closely).