SnorkelForecast.com

Tumon Bay Snorkel Report Today

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

The skinny

Marginal Report Thu 06:29

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

29.3°C

Max air

31.2°C

Sky

Partly cloudy

53% 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 (31 hours)
  • Tide/current (28 hours)
  • Darkness (18 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

Sun 20:00 – Wed 20:00 (ChST)

Previous day Yesterday Next day Live

Snorkel Score (selected 24h)

Best snorkel score is 0.29 around Mon 18:00; 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 0.76m to 0.86m).

Wind is at or below 5.4m/s in 4/24 sampled hours (range 4.4 to 21.4m/s).

Tides range from 0.33m to 1.09m; 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
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
Sun 23:00 0.82 · high 18.60 · high 29.70 · good poor
Mon 00:00 0.82 · high 19.00 · high 29.80 · good poor
Mon 01:00 0.82 · high 18.80 · high 29.80 · good poor
Mon 02:00 0.84 · high 19.80 · high 29.90 · good poor
Mon 03:00 0.84 · high 21.20 · high 29.90 · good poor
Mon 04:00 0.84 · high 20.60 · high 30.00 · good poor
Mon 05:00 0.86 · high 21.40 · high 30.10 · good poor
Mon 06:00 0.86 · high 20.80 · high 30.10 · good poor
Mon 07:00 0.84 · high 18.90 · high 30.10 · good poor
Mon 08:00 0.84 · high 17.80 · high 30.00 · good poor
Mon 09:00 0.82 · high 15.40 · high 30.00 · good poor
Mon 10:00 0.80 · high 12.40 · high 29.90 · good poor
Mon 11:00 0.80 · high 11.50 · high 29.90 · good poor
Mon 12:00 0.78 · high 10.70 · high 29.80 · good poor
Mon 13:00 0.78 · high 10.40 · high 29.80 · good poor
Mon 14:00 0.76 · high 9.90 · high 29.80 · good poor
Mon 15:00 0.76 · high 7.90 · high 29.80 · good poor
Mon 16:00 0.76 · high 5.00 · good 29.70 · good poor
Mon 17:00 0.76 · high 4.60 · good 29.70 · good poor
Mon 18:00 0.76 · high 5.00 · good 29.70 · good poor
Mon 19:00 0.76 · high 4.40 · good 29.70 · good poor
Mon 20:00 0.74 · high 4.20 · good 29.70 · good poor
Mon 21:00 0.74 · high 7.30 · high 29.80 · good poor
Mon 22:00 0.74 · high 7.90 · high 29.80 · good poor
Mon 23:00 0.72 · high 9.20 · high 29.80 · good poor
Tue 00:00 0.72 · high 10.70 · high 29.90 · good poor
Tue 01:00 0.72 · high 12.50 · high 29.90 · good poor
Tue 02:00 0.72 · high 12.00 · high 30.00 · good poor
Tue 03:00 0.72 · high 13.90 · high 30.10 · good poor
Tue 04:00 0.72 · high 15.20 · high 30.20 · good poor
Tue 05:00 0.72 · high 11.00 · high 30.20 · good poor
Tue 06:00 0.72 · high 10.40 · high 30.30 · good poor
Tue 07:00 0.72 · high 8.10 · high 30.30 · good poor
Tue 08:00 0.70 · high 12.50 · high 30.20 · good poor
Tue 09:00 0.70 · high 9.60 · high 30.10 · good poor
Tue 10:00 0.70 · high 12.40 · high 30.10 · good poor
Tue 11:00 0.70 · high 12.80 · high 30.00 · good poor
Tue 12:00 0.72 · high 10.00 · high 30.10 · good poor
Tue 13:00 0.72 · high 9.40 · high 30.00 · good poor
Tue 14:00 0.72 · high 11.90 · high 30.00 · good poor
Tue 15:00 0.72 · high 11.70 · high 30.00 · good poor
Tue 16:00 0.72 · high 12.30 · high 29.90 · good poor
Tue 17:00 0.70 · high 11.10 · high 29.90 · good poor
Tue 18:00 0.70 · high 12.30 · high 29.90 · good poor
Tue 19:00 0.70 · high 9.30 · high 29.90 · good poor
Tue 20:00 0.68 · high 9.70 · high 29.90 · good poor
Tue 21:00 0.68 · high 15.60 · high 29.90 · good poor
Tue 22:00 0.68 · high 16.00 · high 29.90 · good poor
Tue 23:00 0.68 · high 16.90 · high 29.90 · good poor
Wed 00:00 0.68 · high 18.60 · high 29.90 · good poor
Wed 01:00 0.68 · high 21.40 · high 29.90 · good poor
Wed 02:00 0.70 · high 22.50 · high 29.90 · good poor
Wed 03:00 0.70 · high 21.30 · high 30.00 · good poor
Wed 04:00 0.70 · high 20.50 · high 30.00 · good poor
Wed 05:00 0.70 · high 17.60 · high 30.00 · good poor
Wed 06:00 0.70 · high 18.00 · high 30.00 · good poor
Wed 07:00 0.70 · high 16.80 · high 30.00 · good poor
Wed 08:00 0.70 · high 16.20 · high 30.00 · good poor
Wed 09:00 0.70 · high 14.00 · high 30.00 · good poor
Wed 10:00 0.70 · high 11.90 · high 29.90 · good poor
Wed 11:00 0.70 · high 9.90 · high 29.90 · good poor
Wed 12:00 0.70 · high 11.80 · high 29.90 · good poor
Wed 13:00 0.70 · high 14.60 · high 29.90 · good poor
Wed 14:00 0.70 · high 15.20 · high 29.80 · good poor
Wed 15:00 0.70 · high 10.50 · high 29.80 · good poor
Wed 16:00 0.70 · high 11.10 · high 29.80 · good poor
Wed 17:00 0.70 · high 8.80 · high 29.80 · good poor
Wed 18:00 0.70 · high 6.30 · high 29.80 · good poor
Wed 19:00 0.70 · high 7.80 · high 29.80 · good poor