SnorkelForecast.com

Tumon Bay Snorkel Report Today

Guam · Updated Tue 04:16 (ChST) · Source: Snapshot · Showing fallback/stale data

The skinny

Marginal Report Thu 09:33

Tumon Bay looks marginal today. The least-bad daylight window is around Fri 13:00, but waves is limiting the forecast.

Score: 4.7/10

Best time: Fri 13:00

Main risk: Waves

Best morning signal: Thu 11:00 (Fair).

Best afternoon signal: Thu 12:00 (Fair). Peak afternoon wind is about 4.6 m/s.

Email me when it is good

Sunrise

06:03

Sunset

18:51

Water

29.4°C

Max air

31.2°C

Sky

Partly cloudy

45% cloud

No safe window in the next 72 hours

Use the best-available section for the least-bad times.

3-day planner Best available Show data

3-day planner

Thursday

⚠️ fair conditions

Main blocker: Waves

Friday

⚠️ fair conditions

Main blocker: Waves

Best available hours

  • Fri 03:00 — Fair (0.48) · still limited by waves, tide/current
  • Thu 02:00 — Fair (0.47) · still limited by waves
  • Fri 01:00 — Fair (0.41) · still limited by waves, tide/current

Why this verdict

Main blockers across the next 72 hours:

  • Waves (28 hours)
  • Tide/current (25 hours)
  • Darkness (15 hours)

Jellyfish drift risk

Drift estimate from wind, swell, current and warm water.

Low · 34/100

Low drift risk now.

warm water supports seasonal jellyfish activity; surface drift/current is noticeable; local shoreline exposure is not mapped yet.

Sightings override the model: if you see small purple jellyfish with long trailing tentacles, treat them as sting-capable and give them space.

Upcoming high tides

Next early morning high tide: Thu 16:00

Thu 06:00, Thu 16:00

Nearby alternatives in Guam

No nearby alternatives available.

Advanced forecast data

Viewing historical data

Thu 23:00 – Sun 23:00 (ChST)

Previous day Yesterday Next day Live

Snorkel Score (selected 24h)

Best snorkel score is 0.0 around Fri 09:00; 0 of 24 hours are good, fair, or excellent.

Score trend, higher is better. Excellent ≥ 0.72, good 0.55–0.72, fair 0.35–0.55.

Conditions (24h trends)

Tap a chart to load just that series.

0/24 sampled hours stay at or below 0.36m (range 1.0m to 1.24m).

Wind is at or below 5.4m/s in 0/24 sampled hours (range 11.3 to 25.1m/s).

Tides range from 0.43m to 1.11m; 1 of 24 hours are in or near peak slack windows.

72-hour historical overview
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Scoring methodology (for technical users)

We score each hour from 0 to 1 using daylight and these weighted components:

  • Wave height (35%): best below 0.36m, then decreases as it rises.
  • Wind speed (25%): best below 5.4m/s, lower is better.
  • Sea surface temperature (15%): best within 20.6°C to 30.4°C.
  • Tide and currents (15%): best around slack/high-tide windows.
  • Daylight (10%): visibility and safety gate (outside daylight scores lower).
Detailed hourly data table
Time Wave (m) Wind (m/s) Sea temp (°C) Status
Thu 23:00 1.18 · high 22.10 · high 29.80 · good poor
Fri 00:00 1.20 · high 22.40 · high 29.80 · good poor
Fri 01:00 1.22 · high 23.70 · high 29.80 · good poor
Fri 02:00 1.22 · high 23.90 · high 29.80 · good poor
Fri 03:00 1.24 · high 25.10 · high 29.90 · good poor
Fri 04:00 1.22 · high 24.20 · high 29.90 · good poor
Fri 05:00 1.22 · high 23.50 · high 29.90 · good poor
Fri 06:00 1.20 · high 24.10 · high 29.90 · good poor
Fri 07:00 1.18 · high 24.20 · high 29.90 · good poor
Fri 08:00 1.18 · high 20.80 · high 29.90 · good poor
Fri 09:00 1.16 · high 18.20 · high 29.90 · good poor
Fri 10:00 1.14 · high 15.90 · high 29.80 · good poor
Fri 11:00 1.12 · high 17.00 · high 29.80 · good poor
Fri 12:00 1.10 · high 14.30 · high 29.80 · good poor
Fri 13:00 1.08 · high 14.10 · high 29.80 · good poor
Fri 14:00 1.08 · high 17.80 · high 29.70 · good poor
Fri 15:00 1.06 · high 17.00 · high 29.70 · good poor
Fri 16:00 1.06 · high 14.70 · high 29.70 · good poor
Fri 17:00 1.04 · high 14.90 · high 29.70 · good poor
Fri 18:00 1.04 · high 14.80 · high 29.70 · good poor
Fri 19:00 1.02 · high 13.30 · high 29.70 · good poor
Fri 20:00 1.02 · high 14.60 · high 29.70 · good poor
Fri 21:00 1.00 · high 11.30 · high 29.70 · good poor
Fri 22:00 1.00 · high 19.50 · high 29.70 · good poor
Fri 23:00 0.98 · high 16.90 · high 29.70 · good poor
Sat 00:00 0.98 · high 18.50 · high 29.80 · good poor
Sat 01:00 0.96 · high 13.90 · high 29.80 · good poor
Sat 02:00 0.96 · high 9.10 · high 29.90 · good poor
Sat 03:00 0.94 · high 12.00 · high 30.00 · good poor
Sat 04:00 0.94 · high 10.10 · high 30.10 · good poor
Sat 05:00 0.92 · high 13.00 · high 30.20 · good poor
Sat 06:00 0.92 · high 12.60 · high 30.20 · good poor
Sat 07:00 0.92 · high 13.00 · high 30.20 · good poor
Sat 08:00 0.90 · high 13.20 · high 30.20 · good poor
Sat 09:00 0.90 · high 12.10 · high 30.10 · good poor
Sat 10:00 0.90 · high 11.80 · high 30.00 · good poor
Sat 11:00 0.88 · high 13.00 · high 30.00 · good poor
Sat 12:00 0.88 · high 11.90 · high 29.90 · good poor
Sat 13:00 1.06 · high 12.60 · high 29.70 · good poor
Sat 14:00 1.04 · high 17.10 · high 29.70 · good poor
Sat 15:00 1.04 · high 11.10 · high 29.70 · good poor
Sat 16:00 1.04 · high 15.50 · high 29.60 · good poor
Sat 17:00 1.02 · high 11.30 · high 29.60 · good poor
Sat 18:00 1.02 · high 10.90 · high 29.60 · good poor
Sat 19:00 1.00 · high 11.30 · high 29.60 · good poor
Sat 20:00 1.00 · high 10.80 · high 29.60 · good poor
Sat 21:00 0.98 · high 15.50 · high 29.60 · good poor
Sat 22:00 0.98 · high 18.20 · high 29.60 · good poor
Sat 23:00 0.98 · high 19.30 · high 29.70 · good poor
Sun 00:00 0.98 · high 21.10 · high 29.70 · good poor
Sun 01:00 0.98 · high 22.10 · high 29.70 · good poor
Sun 02:00 0.98 · high 22.50 · high 29.80 · good poor
Sun 03:00 0.98 · high 22.20 · high 29.80 · good poor
Sun 04:00 0.98 · high 21.30 · high 29.90 · good poor
Sun 05:00 0.96 · high 20.90 · high 30.00 · good poor
Sun 06:00 0.96 · high 20.70 · high 30.00 · good poor
Sun 07:00 0.96 · high 19.20 · high 30.00 · good poor
Sun 08:00 0.94 · high 17.80 · high 29.90 · good poor
Sun 09:00 0.94 · high 15.80 · high 29.90 · good poor
Sun 10:00 0.92 · high 14.70 · high 29.80 · good poor
Sun 11:00 0.92 · high 15.50 · high 29.80 · good poor
Sun 12:00 0.90 · high 13.00 · high 29.70 · good poor
Sun 13:00 0.90 · high 13.40 · high 29.70 · good poor
Sun 14:00 0.88 · high 12.80 · high 29.70 · good poor
Sun 15:00 0.88 · high 12.40 · high 29.70 · good poor
Sun 16:00 0.88 · high 12.00 · high 29.70 · good poor
Sun 17:00 0.86 · high 11.50 · high 29.70 · good poor
Sun 18:00 0.86 · high 10.00 · high 29.70 · good poor
Sun 19:00 0.86 · high 9.20 · high 29.70 · good poor
Sun 20:00 0.84 · high 8.80 · high 29.70 · good poor
Sun 21:00 0.84 · high 13.80 · high 29.70 · good poor
Sun 22:00 0.84 · high 17.00 · high 29.70 · good poor