SnorkelForecast.com

Tumon Bay Snorkel Report Today

Guam · Updated Sat 05:04 (ChST) · Source: Snapshot · Showing fallback/stale data

The skinny

Marginal Report Mon 00:24

Tumon Bay looks marginal today. The least-bad daylight window is around Tue 10:00, but waves is limiting the forecast.

Score: 4.2/10

Best time: Tue 10:00

Main risk: Waves

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

Best afternoon signal: Mon 18:00 (Fair). Peak afternoon wind is about 5.8 m/s.

Email me when it is good

Sunrise

06:02

Sunset

18:51

Water

29.0°C

Max air

33.0°C

Sky

Cloudy

73% 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

Monday

⚠️ fair conditions

Main blocker: Waves

Tuesday

⚠️ fair conditions

Main blocker: Waves

Best available hours

  • Tue 00:00 — Fair (0.50) · still limited by waves, tide/current
  • Mon 08:00 — Fair (0.42) · still limited by waves, tide/current
  • Tue 01:00 — Fair (0.42) · still limited by waves, tide/current

Why this verdict

Main blockers across the next 72 hours:

  • Waves (38 hours)
  • Tide/current (38 hours)
  • Darkness (24 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: Mon 14:00

Mon 14:00, Tue 03:00

Nearby alternatives in Guam

No nearby alternatives available.

Advanced forecast data

Viewing historical data

Thu 14:00 – Sun 14:00 (ChST)

Previous day Yesterday Next day Live

Snorkel Score (selected 24h)

Best snorkel score is 0.36 around Fri 18:00; 1 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 0.94m to 1.22m).

Wind is at or below 5.4m/s in 17/24 sampled hours (range 2.6 to 6.28m/s).

Tides range from 0.26m to 1.11m; 2 of 24 hours are in or near peak slack windows.

72-hour historical overview
poor ❌ Limited
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fair ⚠️ Fair
poor ❌ Limited
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fair ⚠️ Fair
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
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fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
fair ⚠️ Fair
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
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 14:00 1.22 · high 3.23 · good 28.90 · good poor
Thu 15:00 1.20 · high 3.27 · good 28.90 · good poor
Thu 16:00 1.20 · high 3.96 · good 28.90 · good poor
Thu 17:00 1.18 · high 3.64 · good 28.90 · good poor
Thu 18:00 1.18 · high 4.20 · good 28.90 · good poor
Thu 19:00 1.18 · high 3.59 · good 28.90 · good poor
Thu 20:00 1.16 · high 4.10 · good 28.90 · good poor
Thu 21:00 1.16 · high 4.85 · good 28.90 · good poor
Thu 22:00 1.16 · high 5.98 · high 28.90 · good poor
Thu 23:00 1.16 · high 5.59 · high 28.90 · good poor
Fri 00:00 1.16 · high 5.91 · high 28.90 · good poor
Fri 01:00 1.16 · high 6.07 · high 29.00 · good poor
Fri 02:00 1.14 · high 6.28 · high 29.00 · good poor
Fri 03:00 1.14 · high 5.74 · high 29.00 · good poor
Fri 04:00 1.10 · high 5.37 · good 29.10 · good poor
Fri 05:00 1.08 · high 5.71 · high 29.10 · good poor
Fri 06:00 1.04 · high 5.06 · good 29.10 · good poor
Fri 07:00 1.02 · high 4.98 · good 29.10 · good poor
Fri 08:00 1.00 · high 4.85 · good 29.10 · good fair
Fri 09:00 0.98 · high 3.80 · good 29.10 · good poor
Fri 10:00 0.96 · high 3.46 · good 29.10 · good poor
Fri 11:00 0.96 · high 2.60 · good 29.00 · good poor
Fri 12:00 0.94 · high 4.48 · good 29.00 · good poor
Fri 13:00 0.94 · high 2.80 · good 29.00 · good poor
Fri 14:00 0.92 · high 3.07 · good 29.00 · good poor
Fri 15:00 0.92 · high 2.74 · good 29.00 · good poor
Fri 16:00 0.92 · high 2.45 · good 29.00 · good poor
Fri 17:00 0.90 · high 3.22 · good 29.00 · good poor
Fri 18:00 0.90 · high 3.40 · good 29.00 · good poor
Fri 19:00 0.90 · high 2.60 · good 29.00 · good poor
Fri 20:00 0.88 · high 2.13 · good 29.00 · good poor
Fri 21:00 0.88 · high 3.64 · good 29.00 · good poor
Fri 22:00 0.88 · high 3.61 · good 28.90 · good poor
Fri 23:00 0.86 · high 4.40 · good 29.00 · good poor
Sat 00:00 0.86 · high 4.60 · good 29.00 · good poor
Sat 01:00 0.86 · high 4.56 · good 29.00 · good poor
Sat 02:00 0.88 · high 4.77 · good 29.10 · good poor
Sat 03:00 0.88 · high 5.32 · good 29.20 · good poor
Sat 04:00 0.88 · high 5.02 · good 29.20 · good poor
Sat 05:00 0.90 · high 5.01 · good 29.30 · good poor
Sat 06:00 0.88 · high 4.85 · good 29.10 · good poor
Sat 07:00 0.88 · high 4.44 · good 29.10 · good poor
Sat 08:00 0.86 · high 4.17 · good 29.10 · good fair
Sat 09:00 0.86 · high 3.45 · good 29.00 · good poor
Sat 10:00 0.84 · high 2.97 · good 29.00 · good poor
Sat 11:00 0.84 · high 2.30 · good 29.00 · good poor
Sat 12:00 0.82 · high 2.65 · good 28.90 · good poor
Sat 13:00 0.80 · high 2.43 · good 28.90 · good poor
Sat 14:00 0.80 · high 2.25 · good 28.90 · good poor
Sat 15:00 0.78 · high 2.49 · good 28.90 · good poor
Sat 16:00 0.78 · high 3.11 · good 28.80 · good poor
Sat 17:00 0.76 · high 2.93 · good 28.80 · good poor
Sat 18:00 0.76 · high 2.75 · good 28.80 · good poor
Sat 19:00 0.76 · high 1.68 · good 28.80 · good poor
Sat 20:00 0.76 · high 1.88 · good 28.80 · good poor
Sat 21:00 0.76 · high 2.83 · good 28.80 · good poor
Sat 22:00 0.76 · high 3.09 · good 28.80 · good poor
Sat 23:00 0.74 · high 3.05 · good 28.80 · good poor
Sun 00:00 0.74 · high 3.05 · good 28.90 · good fair
Sun 01:00 0.74 · high 3.14 · good 28.90 · good fair
Sun 02:00 0.72 · high 2.65 · good 29.00 · good fair
Sun 03:00 0.72 · high 2.31 · good 29.10 · good fair
Sun 04:00 0.72 · high 1.17 · good 29.20 · good fair
Sun 05:00 0.72 · high 1.03 · good 29.30 · good fair
Sun 06:00 0.72 · high 1.15 · good 29.30 · good fair
Sun 07:00 0.72 · high 0.20 · good 29.30 · good fair
Sun 08:00 0.72 · high 0.43 · good 29.30 · good fair
Sun 09:00 0.72 · high 1.57 · good 29.30 · good poor
Sun 10:00 0.72 · high 2.55 · good 29.20 · good poor
Sun 11:00 0.72 · high 2.94 · good 29.20 · good poor
Sun 12:00 0.72 · high 3.39 · good 29.10 · good poor
Sun 13:00 0.72 · high 3.18 · good 29.10 · good poor