Swimming Ability: Good. Speed and distance limits are untested. Can swim at least a mile and a half in fresh water. One swam more than 9 miles in the Gulf of Mexico. Can swim to island campsites.
Running Speed: Lean bears can exceed 30 mph. Can run uphill, downhill, or on level ground. Fat bears in winter coats overheat and tire quickly.
http://www.bear.org/Black/Black_Bear_Facts.html