Midway Atoll, United States · Pacific/Midway

North Shore

Genuinely remote, and the only spot in this list where the tide station is the break.

04:00 local · 2026-10-04

69% — the read for this hour

Worth the drive69%

Swell

2.24 m

Period

10 s

Swell from

130°

Wind

12.9 m/s

Wind from

86°

Air

27°C

Worth the drive69%

Worth the drive. At North Shore on this hour the read is 69%. What earns it: swell power at 31.7 kW/m. What costs it: direction match at 98° off the 32° peel.

19 hours worth driving for today: 00:00, 02:00, 03:00, 04:00, 05:00, 06:00, 07:00, 08:00, 09:00, 10:00, 15:00, 16:00, 17:00, 18:00, 19:00, 20:00, 21:00, 22:00, 23:00.

Tide window for a reef pass: 0.9–2 m of water over the take-off; below 0.60 m it needs the pass covered matters and the reef is exposed.

North Shore · 24 hours, local timelive data

score tide (dashed, MLLW) swell height now

Dashed line is the tide above MLLW, solid line is the swell height. Column height is the engine score for that hour. Faded columns are gated. The hour you select is in the URL, so this page is shareable as-is.

Tide station

Station: Midway Atoll
Datum: MLLW
Range: 0.63 m
Mean: 0.29 m

Signature interaction

Drag the tide and watch the reef change its mind

The cross-section is drawn from the break's own reef slope. Every change re-runs the shared engine on the server and returns a fresh seal — this control cannot work without the API.

Seabed cross-section · North ShoreReef pass — a channel cut through the outer barrier reef

Drag the tide — what-if only, nothing stored is changed

0.15 m

The dashed arrow is the peel, at c = √(g·depth). More water over the take-off means a faster peel, which is why the same swell behaves differently at low and mid tide.

Re-solved by swellread-engine/2026.10.1

Worth the drive 69%seal 26fadc770ea2…

Water over take-off: exposed
Break height: 1.15 m
Peel speed: 14.5 km/h
Wave power: 31.7 kW/m

Worth the drive. At North Shore on this hour the read is 69%. What earns it: swell power at 31.7 kW/m. What costs it: direction match at 98° off the 32° peel.

Every factor, re-weighted for this tide

Swell power31.7 kW/m · 22.0%
Peel speed14.5 km/h · 20.0%
Wind quality12.9 m/s 44° off · 0.9%
Tide window1.65 m over the take-off · 18.0%
Direction match98° off the 32° peel · 0.0%
Period cleanliness10.1 s · 8.0%

Show your working

Every factor, its weight, and the arithmetic behind it

Weights are renormalised over the factors that have real data behind them. A factor with no data is dropped and said so, never quietly scored at zero.

Swell power31.7 kW/m · 22.0%
weight 0.220
Peel speed14.5 km/h · 20.0%
weight 0.200
Wind quality12.9 m/s 44° off · 0.9%
weight 0.200
Tide window1.65 m over the take-off · 18.0%
weight 0.180
Direction match98° off the 32° peel · 0.0%
weight 0.120
Period cleanliness10.1 s · 8.0%
weight 0.080

engine seal 26fadc770ea2ed151f132aa895a9cac7a79e7fd32ee02ba3f6d4c3c5dd3a1ca092e8f8dd86a2b87395acf83b2827a76c

Swell power
P = 1/16 · rho · g · Hs² · Tp = 0.628 · 2.24² · 10 = 31.7 kW/m, against a 22 kW/m "serious day" reference.
Peel speed
c = sqrt(g · depth) = sqrt(9.81 · 1.65 m) = 14.5 km/h over a 1.65 m take-off, with 1.15 m standing up. Full marks 8.5–19 km/h: slower is mush, faster than ~25 km/h is unridable.
Wind quality
Wind is 44° off at 12.9 m/s. Alignment = 1 − (1 + cos 44°)/2 = 0.14; speed envelope at 12.9 m/s = 0.30. Product 0.04.
Tide window
reef pass needs the pass covered. Ideal band 0.9–2 m of water over the take-off; below 0.60 m the reef is exposed.
Direction match
Swell from 130°, this break peels cleanly from 32°. 98° of error: inside 12° is full marks, past 75° the swell wraps the headland and does not arrive.
Period cleanliness
Tp = 10.1 s. Energy organises between 6 s and 9.5 s; beyond 14 s the swell stands up steeper than a shallow reef can hold, so the score is eased off by up to 35%.

Provenance

Every number above came from one of these

liveOpen-Meteo Marine APICC BY 4.0, non-commercial attribution requiredfetched 2026-10-04 20:32 UTC168 hourly rows, swell and wind wave.
liveOpen-Meteo Forecast APICC BY 4.0, non-commercial attribution requiredfetched 2026-10-04 20:32 UTC168 hourly rows, wind and air.
liveNOAA CO-OPS tide predictionsU.S. Government public domainfetched 2026-10-04 20:32 UTC144 hourly predictions, MLLW datum, station 1612340 (Midway Atoll).

Snapshot generated 2026-10-04T20:32:06.880Z. Break orientation, reef slope and take-off depth come from this project's catalogue and are labelled as estimates, not survey data.