San Juan Island is not the largest of these islands, but it is the most populous, and is home to the county seat, Friday Harbor, which is the biggest and most developed town in the islands. As the hub of island activity, San Juan Island is home to more whale-watching and sea-kayaking companies than any of the other islands. It also has charter boats, fishing boats, moped rentals, and lots of souvenir shops. This all adds up to crowds in the summer, so if you're looking for an idyllic island getaway, you might want to try Orcas or Lopez.
However, what San Juan Island has going for it is lots of history, plus great views of the Olympic Mountains across the Strait of Juan de Fuca, and it is the only place in the islands where you can reliably see orca whales from shore.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.