The San Juan Islands are 172 named islands scattered across the northeast corner of the Salish Sea, straddling the US–Canada border about 25 nautical miles north of Anacortes. Every PNW sailor has them on a list; most have been; the ones who have been once go back. The cruising attraction is unusual in being uniformly distributed — destination islands, anchorages, wildlife, currents, towns, and weather all of high quality and concentrated in roughly fifty square miles of water. There is no off-season for the worth of the place; only an off-season for visiting it without crowds.
This is the working guide. The flagship anchorages and the named tidal passes get their own sections. The currents — the part of San Juans cruising that catches first-time visitors — are not optional knowledge.
Getting there
From Seattle, the San Juans are 65 nm. Most chartered crews leave from Anacortes (Cap Sante Marina), 25 nm from the islands. This is the practical choice: it maximises time in the islands rather than burning a day on the transit through Puget Sound and Admiralty Inlet.
The main passage north from the south is Rosario Strait, the channel between Fidalgo Island and Decatur–Lopez. Strong currents and commercial shipping traffic make Rosario demanding; check current and weather before committing. The current runs 3–4 knots peak against a 15-knot southerly produces 4-foot short-period chop — uncomfortable in a 35-foot cruising sailboat. The alternative for south-bound boats coming from Bellingham or Anacortes is Guemes Channel, more sheltered and shorter.
For US boats returning from Canadian waters, customs clearance on return is required. CBP ROAM app or the customs dock at Friday Harbor are the standard options. Failure to clear is a federal violation and is enforced.
The four main islands
San Juan Island — the largest and most visited. Friday Harbor (population ~2,000) is the only incorporated town in the archipelago: fuel, provisions, restaurants, chandlery, the Whale Museum, and the customs port. Two US National Historical Park units commemorate the 1859 Pig War — the historical low-stakes border dispute between the US and Britain that produced no human casualties and one dead pig. The west side of the island offers the best orca watching in North America; Lime Kiln Point State Park is the only land-based orca research station in the world.
Orcas Island — the most scenic of the group. Horseshoe-shaped, dominated by 2,409-foot Mount Constitution. Eastsound is the main village. West Sound and Deer Harbor are excellent anchorages with marinas. The northwest quadrant around West Beach offers some of the better anchor spots in the archipelago.
Lopez Island — the flattest, most agricultural, and least visited of the main islands. Slow-paced and friendly — the Lopez Wave is a local custom in which everyone waves at every passing car or boat. Fishermen Bay provides superb protected anchorage and a small marina. Spencer Spit State Park is a must-stop.
Shaw Island — the smallest of the four ferry-served islands. Almost entirely undeveloped. Indian Cove on the south shore is a quiet, protected anchorage with state park facilities.
The flagship anchorages
Garrison Bay (San Juan Island) — protected, calm, and historically significant. English Camp is ashore, with restored buildings open seasonally. Mooring buoys and anchorage. Dinghy to the historic site and walk the loop trail.
Reid Harbor (Stuart Island) — the most photographed anchorage in the islands. A narrow fjord-like bay with mooring buoys and good holding. Stuart Island State Park has trails to Turn Point Lighthouse, with the view across Boundary Pass to Canada that closes most San Juans photo essays.
Prevost Harbor (Stuart Island) — around the corner from Reid Harbor. Excellent holding, quieter, and less visited. The two-harbor stop on Stuart Island — Reid one night, Prevost the next — is a San Juans classic.
Matia Island State Park — tiny, remote, and exquisitely beautiful. Rolfe Cove has four mooring buoys. The forest trail circles the island in 45 minutes. Matia is designated a Natural Area Preserve — stay on the trails.
Jones Island State Park — 188 acres of old-growth forest with 24 mooring buoys and good anchorage in North Bight. River otters (rare in PNW), deer, rabbits, and bald eagles. The sound of the eagles fishing at the bay’s edge in early morning is reliably striking.
Sucia Island — a state park with a complex of coves: Echo Bay, Fossil Bay, Shallow Bay, Snoring Bay. Holding is good across the complex. In peak weekends in July Echo Bay holds 80+ boats; the lesser bays stay quieter.
Tidal currents — the part nobody tells you
The Salish Sea geometry makes the San Juans some of the most tidally complex water on the Pacific Coast. Tides from the Strait of Juan de Fuca, Rosario Strait, and Haro Strait all converge through the same archipelago, producing currents that run hard, reverse on different schedules in adjacent passes, and produce standing waves and rips in the steep gradients between basins.
Cattle Pass (south end of San Juan Island) — 4–5 knots peak. The tide rips here are well-known. In the right conditions — strong ebb against a building southerly — standing waves develop that will stop a 35-foot sailboat cold. Time the transit within 30 minutes of slack. Arrive 20 minutes before slack and watch the whirlpools clear.
San Juan Channel — runs between San Juan and Lopez Islands. 3–4 knots peak. The current reverses every six hours and twelve minutes. Use it rather than fight it.
Rosario Strait — 3–4 knots near peak, with strong wind-against-tide producing 4–6 foot choppy seas. Always check both the current prediction and the wind forecast before committing to a Rosario crossing. The same 3-knot current is two completely different sea states depending on the wind direction.
Obstruction Pass and Peavine Pass — between Orcas, Blakely, and Obstruction islands. 3–4 knots peak. Pleasant with a fair current; a slog against.
Spieden Channel — relatively benign but can have confused seas in wind-against-tide conditions.
The general rule: never plan a passage through a named pass without checking the current prediction for that specific station. NOAA current predictions are accurate to within minutes; using them is the difference between an unremarkable transit and learning the difference between current and tide in the worst possible classroom. See Tides and Currents in the Pacific Northwest for the working framework.
Wildlife
The San Juans are one of the premier marine wildlife destinations in North America, and not by accident — the geography and the salmon runs combine to concentrate sea life in a small area.
Orcas (killer whales). The resident J, K, and L pods of Southern Resident Killer Whales frequent the west side of San Juan Island, particularly in summer when Chinook salmon run close to shore. Lime Kiln Point State Park is the world’s only land-based orca research station. Federal regulations require recreational vessels to maintain 300 yards from southern resident orcas in US waters and 200 yards in Canadian waters. Compliance is enforced; the regulations exist because the population is endangered.
Humpback whales. Increasingly common in the Salish Sea as populations recover. Encountered anywhere but particularly in Rosario Strait.
Harbour seals and Steller sea lions. Seals haul out on every low-lying rock. Sea lions concentrate at Whale Rocks and other named haul-out sites.
Bald eagles. Ubiquitous. Multiple eagles every day is normal.
Dall’s and harbour porpoise. Frequently ride bow waves. The Dall’s especially seem to enjoy boats.
Friday Harbor: the services hub
Friday Harbor is the only incorporated town in the San Juans and the destination for restocking, crew changes, and a taste of island life.
Services. Full fuel dock, pump-out, transient moorage at Port of Friday Harbor (reservations strongly recommended in July–August), grocery store, pharmacy, hardware store, chandlery, and laundry.
Highlights. The Whale Museum (do it), Friday Harbor Brewing Company (do that too), local restaurants focused on fresh seafood. The San Juan Island Farmers Market runs Saturday mornings in summer.
Anchorage. The harbour itself is too busy and deep for most anchoring. Use the marina, or anchor in Westcott Bay 3 miles north.
A classic week
A 7-day San Juan Islands loop from Anacortes:
Day 1: Anacortes → Deer Harbor, Orcas (via Obstruction Pass at slack) Day 2: Deer Harbor → Stuart Island (Reid Harbor) Day 3: Stuart Island → Prevost Harbor (around the corner) → Roche Harbor, San Juan Island Day 4: Roche Harbor → Garrison Bay → west-side orca watching (300-yard standoff) → Friday Harbor Day 5: Friday Harbor layover (Whale Museum, restock, restaurants) Day 6: Friday Harbor → Jones Island → Lopez Island (Fishermen Bay) Day 7: Fishermen Bay → Spencer Spit → Anacortes
Total: approximately 110 nm. Eminently doable for an intermediate crew, with current planning around Cattle Pass on Day 4 and Obstruction Pass on Day 1.
Closing notes
The San Juans are the destination that converts visitors to PNW sailors. A first-time charter from Anacortes in mid-July, with seven days, four anchorages, two ferry-town stops, an orca encounter from the standoff distance, and a Cattle Pass slack transit timed within fifteen minutes of prediction — this is what experienced cruisers point to when asked why they live here.
The currents will test the timing. The wildlife will reward the patience. The anchorages will fill the schedule. Time the slacks. Watch the eagles. Stay 300 yards from the orcas.
Related: Desolation Sound Cruising Guide · Gulf Islands Cruising Guide · Princess Louisa Inlet · Tides and Currents in the PNW · Best Anchorages in the San Juan Islands