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.
00:00 local · 2026-10-04
67% — the read for this hour
Swell
0.80 m
Period
10 s
Swell from
189°
Wind
4.8 m/s
Wind from
56°
Air
26°C
Worth the drive. At Waikiki on this hour the read is 67%. What earns it: peel speed at 12.0 km/h. What costs it: direction match at 77° off the 112° peel.
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.
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.
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
- Water over take-off
- exposed
- Break height
- 0.37 m
- Peel speed
- 12.0 km/h
- Wave power
- 4.1 kW/m
Worth the drive. At Waikiki on this hour the read is 67%. What earns it: peel speed at 12.0 km/h. What costs it: direction match at 77° off the 112° peel.
Every factor, re-weighted for this tide
- Swell power4.1 kW/m · 4.1%
- Peel speed12.0 km/h · 20.0%
- Wind quality4.8 m/s 133° off · 16.8%
- Tide window1.13 m over the take-off · 18.0%
- Direction match77° off the 112° peel · 0.0%
- Period cleanliness10.2 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 power4.1 kW/m · 4.1%
weight 0.220
- Peel speed12.0 km/h · 20.0%
weight 0.200
- Wind quality4.8 m/s 133° off · 16.8%
weight 0.200
- Tide window1.13 m over the take-off · 18.0%
weight 0.180
- Direction match77° off the 112° peel · 0.0%
weight 0.120
- Period cleanliness10.2 s · 8.0%
weight 0.080
engine seal a3004e75e03b21e7aab0db74a32e573e07e3f9be568410cd97d0acfc0c26786403a9c04512e184b18289c132e29c376a
Swell power
P = 1/16 · rho · g · Hs² · Tp = 0.628 · 0.80² · 10 = 4.1 kW/m, against a 22 kW/m "serious day" reference.
Peel speed
c = sqrt(g · depth) = sqrt(9.81 · 1.13 m) = 12.0 km/h over a 1.13 m take-off, with 0.37 m standing up. Full marks 8.5–19 km/h: slower is mush, faster than ~25 km/h is unridable.
Wind quality
Wind is 133° off at 4.8 m/s. Alignment = 1 − (1 + cos 133°)/2 = 0.84; speed envelope at 4.8 m/s = 1.00. Product 0.84.
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 189°, this break peels cleanly from 112°. 77° of error: inside 12° is full marks, past 75° the swell wraps the headland and does not arrive.
Period cleanliness
Tp = 10.2 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 20:29 UTC168 hourly rows, swell and wind wave.
- liveOpen-Meteo Forecast APICC BY 4.0, non-commercial attribution requiredfetched 2026-10-04 20:29 UTC168 hourly rows, wind and air.
- liveNOAA CO-OPS tide predictionsU.S. Government public domainfetched 2026-10-04 20:29 UTC144 hourly predictions, MLLW datum, station 1611400 (Honolulu, Oʻahu).
Snapshot generated 2026-10-04T20:29:17.757Z. Break orientation, reef slope and take-off depth come from this project's catalogue and are labelled as estimates, not survey data.