By Graham Eddy · Sep 17, 2026 · 7 min
A San Juan Islands circuit commonly runs 60 to 100-plus miles over five to eight days, though published club itineraries do roughly 80 nautical miles in four. The spread exists because no single official circumnavigation route exists: paddlers build their own loop between public launches and boat-in marine camps.
That freedom is the trip's appeal and its trap. The currents in Cattle Pass, Spieden Channel and Obstruction Pass can exceed five knots, which is faster than a loaded boat can paddle. Plan legs around slack water rather than around how far you would like to get.
Cold water, close shipping, fast fog
Water here sits at 45 to 55°F year-round — hypothermia in minutes without a dry suit, regardless of how warm the August afternoon feels. Commercial shipping lanes run through Haro and Rosario Straits, and fog banks can drop visibility to zero in minutes, which is a serious combination on a crossing.
Exposed crossings build steep chop and whitecaps in wind. The judgment being asked for is coastal expedition judgment, not flatwater fitness.
Camping is the constraint
No permit is needed to paddle the Salish Sea itself. Overnight camping is almost entirely at Washington State Parks marine-trail sites, which carry a per-night fee and are first-come, or at BLM sites in the San Juan Islands National Monument with their own capacity rules. Cascadia Marine Trail sites are reserved for non-motorized, beachable craft — which is exactly what you are arriving in.
Most marine-trail islands are dry. There is no potable water on sites such as Blind, James or Posey, so carry at least a gallon per person per day and treat resupply as something that happens in towns, not on islands. Many of these islands also have no cell service.
Where people actually launch
The anchors most loops use are Odlin County Park on Lopez Island, Obstruction Pass State Park, and the marine state parks at Jones, Posey and Stuart islands. The classic marine-trail loop runs Friday Harbor to Jones and Stuart. A shorter option, Anacortes to Cypress Island, keeps the crossings brief and adds non-motorized island trails.
June through August is peak season with the year's most stable weather and heavy recreational boat traffic. April and May are cool, wet and quiet. September and October bring morning fog banks, shortening daylight and cooling water. November through March is storm season with high winds and freezing spray — experts only, if at all.
Sharing water with whales
Southern Resident killer whales, harbor seals, Steller sea lions and bald eagles all work these waters, and federal 'Be Whale Wise' rules govern how you behave around them. Know the current rules before launching; they are not advisory.
Build the itinerary from a current table and a marine-camp list, in that order, and the San Juans give you the best island paddling in the country.