If you are coming across Deception Pass, I suspect Keystone is the best launch to use. (next to the ferry)

There is also a launch in Freeland that is closer to Bush Point, but it does not have a dock and is fairly shalow, so check the tides because on a low tide, the water goes way out beyond the end of the concrete.

It should be marked on the map, you will see it in Mutiny bay. You turn right off Hwy 525 onto Fish Road (Stoplight in Freeland), take left onto Woodard and follow that road down to the launch. That will get you close at least, I think there is a turn I missed right close to the launch there, but I would have to have a map to know what the road is. (might be Lancaster Rd.)

Maybe someone else can add that info in. ? Sorry I cannot be more specific.

Good Luck