In the summer months you can swim at Lake Padden Park (4882 Samish Way, 360/676-6985), Lake Samish (673 N. Lake Samish Dr., 360/733-2362), and Bloedel Donovan Park (2214 Electric Ave., 360/676-6985).

Sail the San Juans (360/671-5852 or 800/729-3207, www.stsj.com) offers six-day fully crewed charters around the islands, departing from Bellingham. The visitors bureau has a complete listing of other sailing and fishing charter operators, and cruises.

Moondance Sea Kayaking Adventures (360/738-7664, www.moondancekayak.com) offers guided sea kayak tours from Bellingham. You can rent sea kayaks, rowboats, and sailboats in summer from Bellingham Bay Community Boating Center (501 Harris Ave., 360/647-2469, www.sailpaddlerow.org), near the Bellingham Cruise Terminal.

Bellingham Boat Rentals (3034 Silvern Lane, 360/676-1363) has canoes and pedal boats for rent on Lake Whatcom and is open May through August.

Orca whale-watching trips are becoming increasingly popular from Bellingham, and a number of companies offer these day trips. One of the best is Island Mariner Cruises (5 Harbor Esplanade, 360/734-8866 or 877/734-8866, www.orcawatch.com, $55 for adults, $45 for seniors, or $35 for kids under 16) run by the always-entertaining “Captain Trivia.” Also popular are his 2.5-hour narrated historical harbor cruises for $15 per person. These are offered on Thursday evenings mid-June to mid-August. Tours depart from the boat harbor in town.

San Juan Island Shuttle Express (360/671-1137 or 888/373-8522, www.island-adventures.com) also offers three-hour whale-watching cruises from Bellingham for $65 for adults, or $55 for students.

The Snow Goose (360/733-9078 or 888/877-1770) is a 65-foot fully equipped research vessel operated by two local marine biologists. They offer a range of trips, from one day to five days. On all of these you’ll get a firsthand look at marinelife and how researchers work in Puget Sound. In the summer months they operate along Alaska’s Inside Passage.