SnorkelForecast.com

Tumon Bay Snorkel Report Today

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

The skinny

Marginal Report Wed 13:51

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

No useful morning window is showing yet.

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

Email me when it is good

Sunrise

06:03

Sunset

18:51

Water

29.3°C

Max air

32.3°C

Sky

Cloudy

92% 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 (48 hours)
  • Tide/current (43 hours)
  • Darkness (30 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

Thu 03:00 – Sun 03:00 (ChST)

Previous day Yesterday Next day Live

Snorkel Score (selected 24h)

Best snorkel score is 0.44 around Thu 17:00; 9 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 1.94m to 2.48m).

Wind is at or below 5.4m/s in 24/24 sampled hours (range 1.92 to 5.09m/s).

Tides range from 0.3m to 1.08m; 1 of 24 hours are in or near peak slack windows.

72-hour historical overview
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
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fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
fair ⚠️ Fair
poor ❌ Limited
poor ❌ Limited
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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 03:00 2.14 · high 2.45 · good 29.60 · good fair
Thu 04:00 2.14 · high 2.48 · good 29.80 · good fair
Thu 05:00 2.14 · high 2.50 · good 29.90 · good fair
Thu 06:00 2.14 · high 2.28 · good 29.90 · good fair
Thu 07:00 2.16 · high 1.92 · good 29.90 · good fair
Thu 08:00 2.16 · high 2.27 · good 29.90 · good fair
Thu 09:00 2.48 · high 2.83 · good 29.10 · good poor
Thu 10:00 2.46 · high 2.76 · good 29.10 · good poor
Thu 11:00 2.42 · high 3.03 · good 29.10 · good poor
Thu 12:00 2.40 · high 2.63 · good 29.00 · good poor
Thu 13:00 2.38 · high 2.41 · good 29.00 · good poor
Thu 14:00 2.36 · high 2.46 · good 29.00 · good poor
Thu 15:00 2.34 · high 2.16 · good 29.00 · good poor
Thu 16:00 2.30 · high 2.66 · good 28.90 · good poor
Thu 17:00 2.28 · high 2.55 · good 28.90 · good poor
Thu 18:00 2.24 · high 2.32 · good 28.90 · good poor
Thu 19:00 2.20 · high 3.15 · good 28.90 · good poor
Thu 20:00 2.14 · high 3.18 · good 28.90 · good poor
Thu 21:00 2.10 · high 3.76 · good 29.00 · good poor
Thu 22:00 2.06 · high 3.70 · good 29.00 · good poor
Thu 23:00 2.02 · high 3.98 · good 29.00 · good poor
Fri 00:00 1.98 · high 4.56 · good 29.00 · good fair
Fri 01:00 1.96 · high 4.81 · good 29.10 · good fair
Fri 02:00 1.94 · high 5.09 · good 29.10 · good fair
Fri 03:00 1.92 · high 5.48 · high 29.20 · good fair
Fri 04:00 1.92 · high 5.75 · high 29.30 · good fair
Fri 05:00 1.92 · high 5.98 · high 29.30 · good poor
Fri 06:00 1.92 · high 5.71 · high 29.30 · good poor
Fri 07:00 1.92 · high 5.71 · high 29.30 · good poor
Fri 08:00 1.90 · high 5.24 · good 29.30 · good fair
Fri 09:00 1.90 · high 4.73 · good 29.30 · good poor
Fri 10:00 1.90 · high 4.53 · good 29.20 · good poor
Fri 11:00 1.90 · high 4.26 · good 29.20 · good poor
Fri 12:00 1.90 · high 4.30 · good 29.10 · good poor
Fri 13:00 1.88 · high 4.31 · good 29.10 · good poor
Fri 14:00 1.86 · high 4.48 · good 29.10 · good poor
Fri 15:00 1.84 · high 4.49 · good 29.00 · good poor
Fri 16:00 1.84 · high 4.58 · good 29.00 · good poor
Fri 17:00 1.84 · high 4.53 · good 29.00 · good poor
Fri 18:00 1.84 · high 4.72 · good 29.00 · good poor
Fri 19:00 1.84 · high 4.97 · good 29.00 · good poor
Fri 20:00 1.84 · high 5.77 · high 29.00 · good poor
Fri 21:00 1.84 · high 6.20 · high 29.00 · good poor
Fri 22:00 1.84 · high 6.77 · high 29.00 · good poor
Fri 23:00 1.82 · high 7.02 · high 29.00 · good poor
Sat 00:00 1.82 · high 7.18 · high 29.00 · good poor
Sat 01:00 1.80 · high 7.06 · high 29.00 · good poor
Sat 02:00 1.80 · high 7.49 · high 29.00 · good poor
Sat 03:00 1.78 · high 7.36 · high 29.00 · good poor
Sat 04:00 1.76 · high 7.53 · high 29.00 · good poor
Sat 05:00 1.76 · high 7.47 · high 29.00 · good poor
Sat 06:00 1.74 · high 7.45 · high 29.00 · good poor
Sat 07:00 1.72 · high 7.22 · high 29.00 · good poor
Sat 08:00 1.72 · high 5.87 · high 29.00 · good poor
Sat 09:00 1.70 · high 5.80 · high 29.00 · good poor
Sat 10:00 1.70 · high 6.55 · high 29.00 · good poor
Sat 11:00 1.68 · high 6.77 · high 29.00 · good poor
Sat 12:00 1.68 · high 6.88 · high 29.00 · good poor
Sat 13:00 1.68 · high 7.12 · high 29.00 · good poor
Sat 14:00 1.70 · high 6.94 · high 29.00 · good poor
Sat 15:00 1.70 · high 7.23 · high 28.90 · good poor
Sat 16:00 1.70 · high 7.28 · high 28.90 · good poor
Sat 17:00 1.70 · high 7.25 · high 28.90 · good poor
Sat 18:00 1.70 · high 6.72 · high 28.90 · good poor
Sat 19:00 1.70 · high 6.06 · high 28.90 · good poor
Sat 20:00 1.70 · high 6.71 · high 28.90 · good poor
Sat 21:00 1.70 · high 7.36 · high 28.90 · good poor
Sat 22:00 1.70 · high 7.56 · high 28.90 · good poor
Sat 23:00 1.68 · high 8.02 · high 28.90 · good poor
Sun 00:00 1.68 · high 7.90 · high 28.90 · good poor
Sun 01:00 1.68 · high 7.65 · high 28.90 · good poor
Sun 02:00 1.66 · high 8.12 · high 29.00 · good poor