Free: Contests & Raffles.
Is your boat sound worthy? If so you could go out around the oil docks in edmonds and catch flounder hand over fist. Just drop to bottom, set the hook and reel em up. It wouldn't be hard to catch 100+ in a few hours. Some are decent sized too.
Totally forgot about boat options. Get out while crab is still open and you can pull some pots. Plenty of catching and hopefully do some keeping. Drop a hook with a jig and turkey and drag it along. Flounder city.