When I was up at Fort Worden last summer, some friends took me on a whale watching tour of the San Juan Islands. We stopped for lunch at Friday Harbor. It was an all-day trip and enjoyable, but I would only take it on a day when the weather is clear so you can actually see stuff and it is not too windy. (I got seasick on the way out, which was not good, but was fine on the way back. Take something for nausea with you.)
Here is my blog posting on that day:
http://grandmajjb.blogspot.com/2014/08/ ... -juan.html Hope this helps. Fort Worden, by the way, is a very nice place to stay and you ought to be able to pick all the blackberries you want or at least can get to in the campground!