Wall, Large Rock Formation / Pinnacle, Kelp Forest
Surrounded by walls and shelves, guarded by a barrier of thick kelp and exposed to the currents from Deception Pass make Northwest Island at Rosario Beach a beautiful and exciting dive for the advanced diver. The Outside of the Island and around the points are a series of tall walls extending from the surface to over 100' with ledges, crevasses, and overhangs. The inside of the Island (east side) is less dramatic, mostly large boulders and cascading shelves down to about 45' where it flattens out into the cove of Rosario Beach.
Due to the difficult access to this site and its potential currents, it is teaming with life. Large beds of swimming scallops, huge sea urchins, schools of rockfish and perch, kelp greenling and lingcod, and all sorts of sponges and other invertebrates are just the obvious sights as you enter the water at the island. The west side of the island (outside) and around the points are the most exciting portions to explore.
This site is best as a boat or kayak dive but it can be made from shore by advanced and experienced divers in good physical condition on a slack tide during a very low exchange. The Island is farther than it seems if you attempt to shore dive this site and can put you into some intense current that frequently changes direction. You have a couple options:
Option 1 - Surface Swim: On the surface you will be exposed to the full force of any current running through the bay plus any surface chop. You can find some protection if you follow the cliffs on the north side of the cove, swimming at the base of the rocks until you reach the point then either surface swim or descend and swim to the island. Surprisingly there isn't much to see at the base of the cliffs until you reach the island so you wont be missing much if you choose to surface swim it.
Option 2 - Swim Underwater: Strong swimmers or those with scooters may want to swim it underwater. It is only about 45-50' deep if you swim straight to the island from the beach but it is a long swim, and you still have to come back! The bottom is flat and sandy with no visual reference to shore so take a good compass heading.
Other potential hazards besides current are boat traffic, thick kelp, and occasionally sea lions.
Recommended diving at high tide slack before an ebb for the best visibility. Ebb currents bring in sediments from nearby channels.
How to get there:
Just north of Deception Pass. From WA-20 take Rosario Road to Cougar Gap and turn left. Left again at Rosario Picnic Area Rd. Follow it to the end and park along the road. Hike your gear in along the small dirt trail to the right (north) of the parking lot.
Northwest Island is located directly out from he cove at Rosario Beach to the Northwest side (conveniently named!).
Rosario Beach's Urchin Rocks is located at this beach also, Though not as dynamic and full of life, it is much more accessible and presents less hazards.
Thanks to ChevaYEA for submitting this site!