3 times in December is great, that is a lot more use than most of the boats see.
A lot of our sails are more like 1/3rd of a day sails. In a short day a very nice destination is to reach across to the north end of Bainbridge Island, then tuck into Port Madison for a lunch or snack. It is a pretty quick trip in each direction, we often see porpoises, and Port Madison is a very nice and easy anchorage. If you go slightly farther there is a public dock on the far side of Port Madison with a pizza place at the top.
Two nearby towns to visit are Winslow (Eagle Harbor) on Bainbridge Island and Kingston on the Kitsap Penn. Kingston is a bit shorter of a sail, but going south to Eagle Harbor gives you great views of the city. Both have cheap moorage for 2-3 hours, which gives you time to walk into town and get a meal. I guess Edmonds also qualifies in this way, although I find it to be a less exciting destination.
Blake Island is a fun visit in the off season, but I find it too crowded in the height of summer. The anchoring sucks and the mooring balls are always in use.
Poulsbo and Langley can make for nice quick overnighters, both are about 3-6 hours depending on wind conditions. Poulsbo has the added excitement of going through Agate Pass, which can get moving pretty fast in a spring tide. The first overnighter that my wife and I did was a lap around Bainbridge Island, and that was also pretty fun. It can be done in a day sail, but it would be a long day (I think it is around 40-45 NM starting and ending at Shilshole, and you would need to time currents in Agate Pass and Rich Passage). It can be pretty still on the backside of Bainbridge too.
