Orcas Island: Moran State Park Campgrounds

We camped at Midway, and the boat launch where we saw lots of kayakers was almost just across the road. You can also swim from here, but the roped off swimming area with fishing docks is just up the road a short walk. Cascade Lake is significantly warmer than Mountain Lake, but we found Mountain Lake much quieter and scenic for kayaking, and there's a handy little dock and restrooms right at the entrance to the campsites.
The downhill hike to Cascade Falls is pretty short from its little parking area, but if you head uphill from that parking, there are two more lovely little falls (we saw a young girl diving in and out of the pool at Cave Falls); the third falls past that one isn't worth the walk, though the walk is easy.