Friday Harbor, San Juan Islands is about 13 nautical miles from Anacortes, WA in a straight line, roughly 15 statute miles or 24 kilometers. You cannot run that straight line, though, because you have to weave between islands and through the passes, so a typical on-the-water routing runs about 18 nautical miles. It is the classic short jump-off into the San Juan Islands.
Anacortes to Friday Harbor distance
| Measure | Value |
|---|---|
| Straight-line distance | 13 nautical miles |
| Statute miles | 15 miles |
| Kilometers | 24 km |
| Typical on-the-water routing | about 18 nautical miles |
The straight-line figure of 13 nautical miles is the distance as the crow flies, but the crow does not have islands in the way. You leave Anacortes through Guemes Channel, then thread Thatcher Pass between Decatur and Blakely Islands and run up San Juan Channel to Friday Harbor. That weaving between islands is why the real on-the-water route comes out meaningfully longer, about 18 nautical miles. The water is protected island water the whole way, but the passes run strong reversing tidal currents that can rival a slow boat's speed, so time your transits for slack or a fair current.
How long does it take, and how much fuel, by boat type
These are real numbers from the same engine that powers our boat fuel calculator, run over the 13 nautical mile straight-line distance at a steady cruise. They assume one continuous run, so treat them as the underway total. Plug in your own boat in the calculator below to get your exact figure.
| Boat | Cruise | GPH | MPG | Trip time | Fuel | Fuel cost |
|---|---|---|---|---|---|---|
| 24 ft center console (twin 150s) | 28 mph | 17.2 | 1.6 | 32 min | 9 gal | $41 |
| 38 ft express cruiser (twin gas) | 26 mph | 43.0 | 0.6 | 35 min | 25 gal | $111 |
| 50 ft trawler (single diesel) | 10 mph | 21.7 | 0.5 | 1 hr 30 min | 32 gal | $146 |
Fuel cost assumes $4.50 per gallon. These figures are computed on the 13 nautical mile straight line, but the real on-the-water route through the passes is a bit longer, so pad the fuel a little. Do not just scale from the table: run your own hull, load, and cruise speed.
Estimate the fuel for your own boat
The calculator below is pre-loaded with the Anacortes to Friday Harbor run. Change the engine, horsepower, load, cruise speed, and tank to match your boat and it recomputes the fuel, range, and time instantly.
Best season and weather for the run
Best window: May through September, with July and August the driest and calmest.
This is protected island water, but the passes (Thatcher Pass, then San Juan Channel) run strong reversing tidal currents that can rival a slow boat's speed, so time your transits for slack or a fair current. Fog and frequent ferry traffic mean radar and a sharp watch pay off. On a calm, clear day it is a short and easy cruise into Friday Harbor.
Route notes
- Anacortes / Guemes Channel (0 nm): the departure out of Anacortes. Clear Guemes Channel and set up for the run out to the passes.
- Thatcher Pass (about 6 nm): the gap between Decatur and Blakely Islands. Watch the current through the narrows and keep clear of oncoming traffic in the pass.
- San Juan Channel (13 nm): strong tidal current here, and busy ferry traffic, so time it for a fair current and keep a sharp watch.
- Friday Harbor (18 nm): the town dock and mooring buoys. Approach into the harbor minding the ferry landing and the moored fleet.
Gear to sort before you go
- A fuel system you trust: clean filters and a known tank gauge, so a short run stays a short run.
- Ground tackle sized for the current-swept anchorages and mooring fields of the San Juan Islands.
- A hull and gelcoat in good repair before a coastal run; fix the soft spots and chips at the dock, not at sea.
Need to get the boat run-ready first? See our fuel tanks and systems and marine gelcoats for the repair and maintenance supplies that keep a San Juans run uneventful.
Plan the rest of your trip
Anacortes to Friday Harbor: frequently asked questions
How far is Friday Harbor, San Juan Islands from Anacortes, WA?
Friday Harbor, San Juan Islands is about 13 nautical miles from Anacortes, WA, which is roughly 15 statute miles or 24 kilometers in a straight line. A typical on-the-water routing runs about 18 nautical miles.
How long does it take to get from Anacortes, WA to Friday Harbor, San Juan Islands by boat?
A 24 ft center console (twin 150s) cruising at about 28 mph covers the 13 nautical mile run in roughly 32 minutes. A slower trawler takes much longer, and a fast express cruiser a little less. Use the fuel calculator on this page to plug in your own boat.
How much fuel does the Anacortes, WA to Friday Harbor, San Juan Islands trip use?
The 24 ft center console (twin 150s) burns about 9 gallons on the 13 nautical mile run at roughly 17.2 gallons per hour and 1.6 miles per gallon. Your number depends on horsepower, load, and cruise speed, so run your own boat through the calculator below.
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Updated on 24 June 2026
