Went kayaking at Harstine. There were millions upon millions of finger-sized fish in the water beneath us.
My advice is to use the boat launch just before the bridge. It’s free, and you don’t have to hoof it 250 yards down to the water. The two state parks on the island itself suck.
Oh and there’s a chance of seeing bottle nose dolphins. They showed up in Puget Sound back in the 1990’s.