Keystone Jetty

Keystone Jetty sits at Keystone Harbor on Whidbey Island's central-west shore, inside Fort Casey Historical State Park at Coupeville. The jetty itself is a 75-yard-long sloping boulder pile stretching from the waterline out to about 60 feet of depth, forming a rubble breakwater on the west side of the harbor at the Coupeville-Port Townsend ferry terminal. About 250 yards east of the jetty, an abandoned military wharf still stands 10 yards offshore, with pier pilings running from about 10 feet to 35 feet, and the pilings work as a second dive profile from the same beach. Shore entry is off a smooth-stone beach adjacent to the ferry terminal, and a guide rope with cement-block anchors runs along the bottom to help divers hold position or find their way back in current.

Fort Casey was commissioned in 1897 as a Coast Artillery post, and the disappearing guns and batteries are still on the topside park along with the 1903 Admiralty Head Lighthouse above the dive area. The old wharf east of the jetty is the remnant that supports the second profile below the water. In the dive literature, Keystone is cited as a cornerstone of the Whidbey Island experience and one of the most popular sites in the state, capable of being enjoyed by divers of every skill level. Wolf eels are commonly encountered here and have been documented at 55 feet on the jetty, with juveniles and adults both observed on repeat dives.

The rocky reef biome runs the full length of the jetty and out across the pilings of the old wharf, where the boulder-and-piling structure and strong tidal flow support a dense invertebrate community, resident giant Pacific octopus, and the lingcod and rockfish that define the site. A kelp forest biome grows on the shallower reaches of the boulder pile where bull kelp anchors on the rock and reaches to the surface. The dive is scuba-primary, but the shallow pilings are worked by snorkelers as well, and current sensitivity climbs quickly at the jetty tip and toward the active ferry lane.

The Fort Casey lot serves the dive, with restrooms, drinking water, showers, and a ranger station on site; a Discover Pass is required at $10 a day or $45 a year, and park hours run 8 a.m. to dusk year-round. Ferry runs from the adjacent Coupeville-Port Townsend terminal are a scheduled hazard, and the standing rule is not to go around the corner into the ferry lane. Take of all fish and shellfish is prohibited within the Keystone Conservation Area, the narrow band from the jetty to the eastern side of the old military wharf out to 600 feet offshore, and take of all species except sea urchins and sea cucumbers is prohibited within the adjacent Admiralty Head Marine Preserve to the west, both enforced by WDFW, with rockfish also closed throughout Marine Area 9 and wolf eel and giant Pacific octopus protected non-take statewide.