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.

13:00 local · 2026-10-04

59% — the read for this hour

Worth the drive59%

Swell

1.44 m

Period

6 s

Swell from

138°

Wind

9.1 m/s

Wind from

112°

Air

26°C

Worth the drive59%

Worth the drive. At Pago Pago on this hour the read is 59%. What earns it: peel speed at 15.0 km/h. What costs it: period cleanliness at 6.4 s.

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.

Pago Pago · 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: 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.

Seabed cross-section · Pago PagoReef pass — a channel cut through the outer barrier reef

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

0.67 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 59%seal 46099e185779…

Water over take-off: exposed
Break height: 0.78 m
Peel speed: 15.0 km/h
Wave power: 8.3 kW/m

Worth the drive. At Pago Pago on this hour the read is 59%. What earns it: peel speed at 15.0 km/h. What costs it: period cleanliness at 6.4 s.

Every factor, re-weighted for this tide

Swell power8.3 kW/m · 8.3%
Peel speed15.0 km/h · 20.0%
Wind quality9.1 m/s straight onshore · 0.9%
Tide window1.77 m over the take-off · 18.0%
Direction match17° off the 155° peel · 11.8%
Period cleanliness6.4 s · 0.3%

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 power8.3 kW/m · 8.3%
weight 0.220
Peel speed15.0 km/h · 20.0%
weight 0.200
Wind quality9.1 m/s straight onshore · 0.9%
weight 0.200
Tide window1.77 m over the take-off · 18.0%
weight 0.180
Direction match17° off the 155° peel · 11.8%
weight 0.120
Period cleanliness6.4 s · 0.3%
weight 0.080

engine seal 46099e18577936953dd031e33cee0090a2cdca4cbea1bb3ac2ab906c9f407d6718549ae113445dfcc19a769381c29b6e

Swell power
P = 1/16 · rho · g · Hs² · Tp = 0.628 · 1.44² · 6 = 8.3 kW/m, against a 22 kW/m "serious day" reference.
Peel speed
c = sqrt(g · depth) = sqrt(9.81 · 1.77 m) = 15.0 km/h over a 1.77 m take-off, with 0.78 m standing up. Full marks 8.5–19 km/h: slower is mush, faster than ~25 km/h is unridable.
Wind quality
Wind is straight onshore at 9.1 m/s. Alignment = 1 − (1 + cos 26°)/2 = 0.05; speed envelope at 9.1 m/s = 0.90. Product 0.05.
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 138°, this break peels cleanly from 155°. 17° of error: inside 12° is full marks, past 75° the swell wraps the headland and does not arrive.
Period cleanliness
Tp = 6.4 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.