Tutuila, American Samoa · Pacific/Pago_Pago
Pago Pago
The harbour mouth stands up out of the barrier reef and peels hard left on a big south pulse. It is the reason this app exists: the numbers that make it work arrive days before anyone can see them.
04:00 local · 2026-10-04
69% — the read for this hour
Swell
1.28 m
Period
8 s
Swell from
174°
Wind
9.2 m/s
Wind from
116°
Air
26°C
Worth the drive. At Pago Pago on this hour the read is 69%. What earns it: peel speed at 14.9 km/h. What costs it: wind quality at 9.2 m/s 58° 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 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.
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
- Pago Pago, American Samoa
- Datum
- MLLW
- Range
- 0.97 m
- Mean
- 0.43 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
- 0.69 m
- Peel speed
- 14.9 km/h
- Wave power
- 8.7 kW/m
Worth the drive. At Pago Pago on this hour the read is 69%. What earns it: peel speed at 14.9 km/h. What costs it: wind quality at 9.2 m/s 58° off.
Every factor, re-weighted for this tide
- Swell power8.7 kW/m · 8.7%
- Peel speed14.9 km/h · 20.0%
- Wind quality9.2 m/s 58° off · 4.2%
- Tide window1.75 m over the take-off · 18.0%
- Direction match19° off the 155° peel · 11.6%
- Period cleanliness8.4 s · 6.1%
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 power8.7 kW/m · 8.7%
weight 0.220
- Peel speed14.9 km/h · 20.0%
weight 0.200
- Wind quality9.2 m/s 58° off · 4.2%
weight 0.200
- Tide window1.75 m over the take-off · 18.0%
weight 0.180
- Direction match19° off the 155° peel · 11.6%
weight 0.120
- Period cleanliness8.4 s · 6.1%
weight 0.080
engine seal d99378f2811ee09af3c4361a5097276fedb4b328b8c22777be70c9189872f712f88041b34693642fd386d9e28baa0032
Swell power
P = 1/16 · rho · g · Hs² · Tp = 0.628 · 1.28² · 8 = 8.7 kW/m, against a 22 kW/m "serious day" reference.
Peel speed
c = sqrt(g · depth) = sqrt(9.81 · 1.75 m) = 14.9 km/h over a 1.75 m take-off, with 0.69 m standing up. Full marks 8.5–19 km/h: slower is mush, faster than ~25 km/h is unridable.
Wind quality
Wind is 58° off at 9.2 m/s. Alignment = 1 − (1 + cos 58°)/2 = 0.24; speed envelope at 9.2 m/s = 0.89. Product 0.21.
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 174°, this break peels cleanly from 155°. 19° of error: inside 12° is full marks, past 75° the swell wraps the headland and does not arrive.
Period cleanliness
Tp = 8.4 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 19:09 UTC168 hourly rows, swell and wind wave.
- liveOpen-Meteo Forecast APICC BY 4.0, non-commercial attribution requiredfetched 2026-10-04 19:09 UTC168 hourly rows, wind and air.
- liveNOAA CO-OPS tide predictionsU.S. Government public domainfetched 2026-10-04 19:09 UTC144 hourly predictions, MLLW datum, station 1770000 (Pago Pago, American Samoa).
Snapshot generated 2026-10-04T19:09:21.263Z. Break orientation, reef slope and take-off depth come from this project's catalogue and are labelled as estimates, not survey data.