SnorkelForecast.com

Tumon Bay Snorkel Report Today

Guam · Updated Tue 04:16 (ChST) · Source: Snapshot

The skinny

Marginal Report Wed 07:14

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: Wed 10:00 (Fair).

Best afternoon signal: Wed 18:00 (Fair). Peak afternoon wind is about 4.2 m/s.

Email me when it is good

Sunrise

06:02

Sunset

18:51

Water

29.1°C

Max air

32.7°C

Sky

Partly cloudy

55% 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

Wednesday

⚠️ fair conditions

Main blocker: Waves

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
  • Wed 08:00 — Fair (0.47) · still limited by waves, tide/current
  • Thu 02:00 — Fair (0.47) · still limited by waves

Why this verdict

Main blockers across the next 72 hours:

  • Waves (54 hours)
  • Tide/current (49 hours)
  • Darkness (32 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: Wed 15:00

Wed 05:00, Wed 15:00, Thu 06:00, Thu 16:00

Nearby alternatives in Guam

No nearby alternatives available.

Advanced forecast data

Viewing historical data

Sun 21:00 – Wed 21:00 (ChST)

Previous day Yesterday Next day Live

Snorkel Score (selected 24h)

Best snorkel score is 0.32 around Mon 16:00; 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 1.06m to 1.36m).

Wind is at or below 5.4m/s in 23/24 sampled hours (range 3.73 to 5.71m/s).

Tides range from 0.09m to 1.11m; 2 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 21:00 1.36 · high 4.42 · good 28.90 · good poor
Sun 22:00 1.34 · high 4.34 · good 28.90 · good poor
Sun 23:00 1.32 · high 5.71 · high 28.90 · good poor
Mon 00:00 1.30 · high 5.38 · good 28.90 · good poor
Mon 01:00 1.28 · high 5.31 · good 29.00 · good poor
Mon 02:00 1.24 · high 5.34 · good 29.00 · good poor
Mon 03:00 1.22 · high 5.31 · good 29.00 · good poor
Mon 04:00 1.20 · high 4.91 · good 29.10 · good poor
Mon 05:00 1.18 · high 4.36 · good 29.10 · good poor
Mon 06:00 1.16 · high 4.32 · good 29.10 · good poor
Mon 07:00 1.14 · high 4.81 · good 29.10 · good poor
Mon 08:00 1.14 · high 4.95 · good 29.10 · good poor
Mon 09:00 1.12 · high 4.48 · good 29.10 · good poor
Mon 10:00 1.10 · high 5.12 · good 29.00 · good poor
Mon 11:00 1.08 · high 3.73 · good 29.00 · good poor
Mon 12:00 1.06 · high 4.00 · good 29.00 · good poor
Mon 13:00 1.06 · high 4.72 · good 29.00 · good poor
Mon 14:00 1.06 · high 4.71 · good 28.90 · good poor
Mon 15:00 1.06 · high 5.10 · good 28.90 · good poor
Mon 16:00 1.10 · high 5.16 · good 28.90 · good poor
Mon 17:00 1.12 · high 5.10 · good 28.90 · good poor
Mon 18:00 1.16 · high 4.76 · good 28.90 · good poor
Mon 19:00 1.20 · high 4.95 · good 28.90 · good poor
Mon 20:00 1.24 · high 5.13 · good 28.90 · good poor
Mon 21:00 1.28 · high 5.46 · high 28.90 · good poor
Mon 22:00 1.28 · high 6.07 · high 28.90 · good poor
Mon 23:00 1.30 · high 6.94 · high 28.90 · good poor
Tue 00:00 1.30 · high 7.31 · high 28.90 · good poor
Tue 01:00 1.30 · high 7.59 · high 28.90 · good poor
Tue 02:00 1.30 · high 7.59 · high 29.00 · good poor
Tue 03:00 1.30 · high 7.88 · high 29.00 · good poor
Tue 04:00 1.34 · high 8.29 · high 29.00 · good poor
Tue 05:00 1.36 · high 8.30 · high 29.00 · good poor
Tue 06:00 1.40 · high 6.82 · high 29.00 · good poor
Tue 07:00 1.42 · high 5.81 · high 29.00 · good poor
Tue 08:00 1.42 · high 7.87 · high 29.00 · good poor
Tue 09:00 1.44 · high 7.05 · high 29.00 · good poor
Tue 10:00 1.44 · high 7.48 · high 29.00 · good poor
Tue 11:00 1.42 · high 6.81 · high 29.00 · good poor
Tue 12:00 1.42 · high 6.75 · high 29.00 · good poor
Tue 13:00 1.42 · high 7.09 · high 29.00 · good poor
Tue 14:00 1.44 · high 5.91 · high 29.00 · good poor
Tue 15:00 1.44 · high 5.72 · high 28.90 · good poor
Tue 16:00 1.48 · high 4.50 · good 28.90 · good poor
Tue 17:00 1.52 · high 4.32 · good 28.90 · good poor
Tue 18:00 1.56 · high 2.89 · good 28.90 · good poor
Tue 19:00 1.56 · high 7.34 · high 28.90 · good poor
Tue 20:00 1.54 · high 8.08 · high 28.90 · good poor
Tue 21:00 1.54 · high 7.83 · high 28.90 · good poor
Tue 22:00 1.54 · high 9.05 · high 28.90 · good poor
Tue 23:00 1.52 · high 9.42 · high 28.90 · good poor
Wed 00:00 1.52 · high 9.24 · high 28.90 · good poor
Wed 01:00 1.52 · high 9.60 · high 28.90 · good poor
Wed 02:00 1.54 · high 9.30 · high 29.00 · good poor
Wed 03:00 1.54 · high 8.45 · high 29.00 · good poor
Wed 04:00 1.54 · high 8.16 · high 29.00 · good poor
Wed 05:00 1.52 · high 6.99 · high 29.00 · good poor
Wed 06:00 1.52 · high 6.67 · high 29.00 · good poor
Wed 07:00 1.36 · high 8.13 · high 29.10 · good poor
Wed 08:00 1.36 · high 2.78 · good 29.10 · good fair
Wed 09:00 1.34 · high 2.91 · good 29.00 · good poor
Wed 10:00 1.32 · high 3.16 · good 29.00 · good poor
Wed 11:00 1.28 · high 4.18 · good 29.00 · good poor
Wed 12:00 1.26 · high 4.81 · good 29.00 · good poor
Wed 13:00 1.24 · high 4.75 · good 29.00 · good poor
Wed 14:00 1.20 · high 3.58 · good 29.00 · good poor
Wed 15:00 1.18 · high 4.81 · good 28.90 · good poor
Wed 16:00 1.18 · high 4.30 · good 28.90 · good poor
Wed 17:00 1.18 · high 3.75 · good 28.90 · good poor
Wed 18:00 1.18 · high 3.76 · good 28.90 · good poor
Wed 19:00 1.20 · high 4.56 · good 28.90 · good poor
Wed 20:00 1.22 · high 4.41 · good 28.90 · good poor