Oʻahu, United States · Pacific/Honolulu

Waikiki

Long, slow, shallow. Peel speed is the whole game here, and peel speed is depth, and depth is tide.

20:00 local · 2026-10-04

57% — the read for this hour

Worth the drive57%

Swell

0.66 m

Period

8 s

Swell from

88°

Wind

5.4 m/s

Wind from

53°

Air

24°C

Worth the drive57%

Worth the drive. At Waikiki on this hour the read is 57%. What earns it: peel speed at 11.8 km/h. What costs it: wind quality at 5.4 m/s 35° off.

24 hours worth driving for today: 00:00, 01:00, 02:00, 03:00, 04:00, 05:00, 06:00, 07:00, 08:00, 09:00, 10:00, 11:00, 12:00, 13:00, 14:00, 15:00, 16:00, 17:00, 18:00, 19:00, 20:00, 21:00, 22:00, 23:00.

Tide window for a reef: 0.6–1.4 m of water over the take-off; below 0.40 m it wants the reef just covered matters and the reef is exposed.

Waikiki · 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: Honolulu, Oʻahu
Datum: MLLW
Range: 0.58 m
Mean: 0.30 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 · WaikikiFringing reef — the swell stands up on a shallow shelf

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 57%seal 21de45bc989e…

Water over take-off: exposed
Break height: 0.31 m
Peel speed: 11.8 km/h
Wave power: 2.1 kW/m

Worth the drive. At Waikiki on this hour the read is 57%. What earns it: peel speed at 11.8 km/h. What costs it: wind quality at 5.4 m/s 35° off.

Every factor, re-weighted for this tide

Swell power2.1 kW/m · 2.1%
Peel speed11.8 km/h · 20.0%
Wind quality5.4 m/s 35° off · 1.8%
Tide window1.10 m over the take-off · 18.0%
Direction match24° off the 112° peel · 10.9%
Period cleanliness7.7 s · 3.8%

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 power2.1 kW/m · 2.1%
weight 0.220
Peel speed11.8 km/h · 20.0%
weight 0.200
Wind quality5.4 m/s 35° off · 1.8%
weight 0.200
Tide window1.10 m over the take-off · 18.0%
weight 0.180
Direction match24° off the 112° peel · 10.9%
weight 0.120
Period cleanliness7.7 s · 3.8%
weight 0.080

engine seal 21de45bc989e57fc43671aa57484346b3e71ae05e9d43bdc552d1525b6d49deff3919989b87acdbf17079ca9b84851b5

Swell power
P = 1/16 · rho · g · Hs² · Tp = 0.628 · 0.66² · 8 = 2.1 kW/m, against a 22 kW/m "serious day" reference.
Peel speed
c = sqrt(g · depth) = sqrt(9.81 · 1.10 m) = 11.8 km/h over a 1.10 m take-off, with 0.31 m standing up. Full marks 8.5–19 km/h: slower is mush, faster than ~25 km/h is unridable.
Wind quality
Wind is 35° off at 5.4 m/s. Alignment = 1 − (1 + cos 35°)/2 = 0.09; speed envelope at 5.4 m/s = 1.00. Product 0.09.
Tide window
reef wants the reef just covered. Ideal band 0.6–1.4 m of water over the take-off; below 0.40 m the reef is exposed.
Direction match
Swell from 88°, this break peels cleanly from 112°. 24° of error: inside 12° is full marks, past 75° the swell wraps the headland and does not arrive.
Period cleanliness
Tp = 7.7 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 21:10 UTC168 hourly rows, swell and wind wave.
liveOpen-Meteo Forecast APICC BY 4.0, non-commercial attribution requiredfetched 2026-10-04 21:10 UTC168 hourly rows, wind and air.
liveNOAA CO-OPS tide predictionsU.S. Government public domainfetched 2026-10-04 21:10 UTC144 hourly predictions, MLLW datum, station 1611400 (Honolulu, Oʻahu).

Snapshot generated 2026-10-04T21:10:32.169Z. Break orientation, reef slope and take-off depth come from this project's catalogue and are labelled as estimates, not survey data.