Boulder Reef
Dive site · United States
Advanced divers and up
Is it worth the trip?
60Good out of 100 for your dates
Best on Mon 2: Sea: flat, Visibility under 5 m, Water 9 °C
Mon 2 · 65 out of 100
- Sea
- 0.0 mflat
- Wind
- 2 kn
- Gusts
- 4kn
- Air
- 9°C
Tue 3 · 64 out of 100
- Sea
- 0.0 mflat
- Wind
- 4 kn
- Gusts
- 5kn
- Air
- 11°C
Wed 4 · 63 out of 100
- Sea
- 0.0 mflat
- Wind
- 8 kn
- Gusts
- 13kn
- Air
- 12°C
Thu 5 · 57 out of 100
- Sea
- 0.1 mflat
- Wind
- 15 kn
- Gusts
- 18kn
- Air
- 12°C
Fri 6 · 58 out of 100
- Sea
- 0.2 mflat
- Wind
- 12 kn
- Gusts
- 22kn
- Air
- 11°C
Sat 7 · 64 out of 100
- Sea
- 0.0 mflat
- Wind
- 5 kn
- Gusts
- 11kn
- Air
- 13°C
Sun 8 · 26 out of 100
- Sea
- 0.2 mflat
- Wind
- 17 kn
- Gusts
- 30knboats in
- Air
- 12°C
Tap a day for sea, wind and water. Full forecast
Forecast: next 10 days
Full forecast- Sun 167, good
- Mon 265, good
- Tue 364, good
- Wed 463, good
- Thu 557, fair
- Fri 658, fair
- Sat 764, good
- Sun 826, poor
- Mon 964, good
- Tue 1056, fair
The site in five facts
- Down to 18 mits deepest
- From a boathow you get in
- Advancedand up
- Water 9 °Cdrysuit
- Faces NWswell from there reaches it
Full forecast
every day, every number
The score doesn't know currents, the visibility on the day or your certification.
Suits Advanced divers and up, as a dive guide states it. Scored for Advanced divers.
| Day | Score | Sea | Wind | Gusts | Air |
|---|---|---|---|---|---|
| Sun 1Nov | 67, good | 0.0 mflat | 2 kn | 4kn | 8°C |
| Mon 2Nov | 65, good | 0.0 mflat | 2 kn | 4kn | 9°C |
| Tue 3Nov | 64, good | 0.0 mflat | 4 kn | 5kn | 11°C |
| Wed 4Nov | 63, good | 0.0 mflat | 8 kn | 13kn | 12°C |
| Thu 5Nov | 57, fair | 0.1 mflat | 15 kn | 18kn | 12°C |
| Fri 6Nov | 58, fair | 0.2 mflat | 12 kn | 22kn | 11°C |
| Sat 7Nov | 64, good | 0.0 mflat | 5 kn | 11kn | 13°C |
| Sun 8Nov | 26, poor | 0.2 mflat | 17 kn | 30knboats in | 12°C |
| Mon 9Nov | 64, good | 0.0 mflat | 3 kn | 7kn | 12°C |
| Tue 10Nov | 56, fair | 0.2 mflat | 13 kn | 17kn | 13°C |
Sea is the waves near the site, in metres; wind and gusts in knots. "Boats in": gusts that keep dive boats in. More
Tide
- Sun 1 NovLow 00:22 −1.4 mHigh 09:57 +0.4 mLow 13:09 +0.3 mHigh 17:00 +0.7 m
- Mon 2 NovLow 01:36 −1.2 mHigh 09:44 +0.5 mLow 14:36 −0.0 mHigh 18:42 +0.4 m
- Tue 3 NovLow 02:42 −1.0 mHigh 09:42 +0.5 mLow 15:37 −0.4 mHigh 20:37 +0.4 m
Local clock times; heights about mean sea level. On open coasts the times are usually within a quarter of an hour; in bays, estuaries and on the Gulf of Mexico they can be an hour or more out. Slack water, the safest time to dive where there is current, is about half an hour either side of each high and low. Tide: EOT20 global ocean tide model, Hart-Davis et al. 2021, DGFI-TUM (doi:10.17882/79489), CC BY 4.0. Times and heights computed by us. A model, not a tide table: check a local table before you go.
Forecast updated . It refreshes every three hours. Forecast data: ECMWF, DWD, Météo-France and NOAA, served by Open-Meteo.com (CC BY 4.0). Changed by us. Generated using E.U. Copernicus Marine Service Information.
Map
the site and its town
Boulder Reef on Google Maps · Directions
Each place wears its best day on these dates: green good, amber fair, pale red poor, as the key says.
The map needs JavaScript. Every place on it is listed on this page, and each place's page links to Google Maps.
One finger scrolls the page; two fingers move the map. Pins are our own positions. Map OpenFreeMap, © OpenMapTiles, data © OpenStreetMap contributors.
More diving near here
1 place
- Bakers Reef 5.5 km away
About
the place in full, sources, credits
About Boulder Reef
A reef dive. It goes down to 18 m. You get in from a boat. It suits Advanced divers and up, as a dive guide states it. The coast faces NW: swell from the NW reaches it, and wind from the SE blows out to sea. No dive centre within 10 km, the nearest 16 km away. The sea is about 8°C in January, its coldest month (drysuit), and 12°C in August, its warmest (7 mm semi-dry or a drysuit). The town to stay in is Lummi Island. Within 5 km we also list 2 dive sites.
- What it is Reef.
- How deep Down to 18 m.
- Getting in From a boat.
- Who it suits Suits Advanced divers and up, as a dive guide states it.
- Dive centres No dive centre within 10 km, the nearest 16 km away.
Water about 9°C: drysuit. Typical sea temperature for the time of year, not a forecast.
Visibility under 5 m. Typical for the time of year, estimated from ten years of NASA satellite water clarity, not a forecast. Clearest in Jan, Feb, Mar, Apr, Oct and Nov (under 5 m).
The score is the conditions only: the journey, the price and the partners never change it (how we score, how we earn).
Rough cost (estimate): about US$1,050–US$1,910 each
about US$1,050–US$1,910 each · 6 nights, 2 sharing: flights, hire car, stay, food.
Our estimate from typical public prices, not a quote: check the real prices before you book (where they come from). Prices are about, in US Dollar (USD): our pound figures at the European Central Bank's rate of 30 October 2026.
How we worked it out
| What | How we worked it out | Each |
|---|---|---|
| Flights | return MDW to SEA, estimated from distance and season, 1 airline on the route, with a hold bag | about US$248–US$516 |
| Hire car | 6 days, shared | about US$154–US$255 |
| Stay | 6 nights, a mid-range double, shared | about US$301–US$502 |
| Food | 7 days eating out | about US$342–US$636 |
| Total | about US$1,050–US$1,910 |
Guided dives are not priced yet: we have no sourced price, so it is not in it. Prices from public sources, checked in 2026.
Where to stay: Lummi Island
18 min by car · 2 places to stay
about US$114/nightcountry average
About Lummi Island its beds, food and every spot near it
About US$114 a night is our estimate of the country's average 2-star double room that month: not each town's price, and not a quote. Drives are estimates. Prices are about, in US Dollar (USD): our pound figures at the European Central Bank's rate of 30 October 2026.
Getting there: about 8h 45m
About 8h 45m door to door from Chicago
Fly MDW → SEA, direct, then 2h 45m by road
Flights MDW → SEA on your dates · Skyscanner
An estimate, one way; the journey never changes the score.
In the water
Dives and courses in Lummi Island · GetYourGuideDive gear hire in Lummi Island · GetYourGuide
Dive centres nearby
The nearest named dive centres and shops within 25 km, in a straight line; training agencies where the map states them. Listings, not a recommendation. Dive centres: © OpenStreetMap contributors (ODbL). Credits
What you might see
Too few open records near this site to list its animals. Ask a dive centre what you are likely to see.
This week: visibility about 8 m, clearer than usual (satellite plankton reading, 24 Oct). Estimated from the month's typical visibility and this week's satellite chlorophyll against the site's normal; heavy rain before a dive can still muddy it.
The current and the life no free forecast gives. Ask a dive centre before you book.