Twanoh State Park is a 182 acre marine park with camping, a boat launch and a long sloping shoreline. Due to it's location in south Hood Canal, it provides the warmest saltwater in Washington State.

Twanoh has no remarkable diving structure but currents are minimal and the gradual sloping bottom is available to all levels of divers. The shoreline along the entire park is easily accessible but the best diving will be found on the east end of the park (to the right as you pull in). The gradual slope is steeper on this end. On low tides it will be a short walk from the parking lot to the water over cobblestone rocks and then transitions to gravelly substrate then to silty sand. The slope continues past beginner diving recommendations of 60' but is predominately silty sand beyond this point.

Eel grass runs the length of the park in the safety stop area during high tides. and large beds of oysters can be observed. Keep an eye out for gobies, sticklebacks, starfish, cucumbers, anemones (especially tube anemones), moon snails, sea pens, flatfish, etc. Perch will often be observed in the eel grass.