SnorkelForecast.com

Tumon Bay Snorkel Report Today

Guam · Updated Wed 01:06 (ChST) · Source: Snapshot

The skinny

Marginal Report Wed 11:16

Tumon Bay looks marginal today. The least-bad daylight window is around Fri 18:00, but waves is limiting the forecast.

Score: 3.5/10

Best time: Fri 18:00

Main risk: Waves

No useful morning window is showing yet.

Best afternoon signal: Wed 18:00 (Poor). Peak afternoon wind is about 4.3 m/s.

Email me when it is good

Sunrise

06:09

Sunset

18:31

Water

29.5°C

Max air

29.6°C

Sky

Cloudy

99% cloud

No good model 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

❌ Poor conditions

Main blocker: Waves

Thursday

❌ Poor conditions

Main blocker: Waves

Friday

⚠️ Fair conditions

Main blocker: Waves

Best available hours

  • Fri 08:00: Fair (0.36) · still limited by waves, wind
  • Wed 08:00: Poor (0.35) · still limited by waves, tide/current
  • Wed 07:00: Poor (0.34) · still limited by waves, tide/current

Why this verdict

Main blockers across the next 72 hours:

  • Waves (71 hours)
  • Tide/current (70 hours)
  • Darkness (45 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

Wed 12:00, Fri 04:00

Nearby alternatives in Guam

No nearby alternatives available.

Advanced forecast data

Viewing current forecast

Wed 01:00 – Sat 01:00 (ChST)

Previous day Yesterday

Snorkel Score (next 24h)

Best snorkel score is 0.35 around Wed 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 1.12m to 1.4m).

Wind is at or below 5.4m/s in 22/24 sampled hours (range 0.67 to 8.74m/s).

Tides range from 0.34m to 1.03m; 1 of 24 hours are in or near peak slack windows.

72-hour forecast 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 is better in daylight, so night hours score lower.
Detailed hourly data table
Time Wave (m) Wind (m/s) Sea temp (°C) Status
Wed 02:00 1.16 · high 3.98 · good 29.50 · good Poor
Wed 03:00 1.16 · high 4.34 · good 29.50 · good Poor
Wed 04:00 1.16 · high 3.98 · good 29.60 · good Poor
Wed 05:00 1.16 · high 3.65 · good 29.60 · good Poor
Wed 06:00 1.16 · high 3.36 · good 29.60 · good Poor
Wed 07:00 1.14 · high 3.32 · good 29.60 · good Poor
Wed 08:00 1.14 · high 3.01 · good 29.60 · good Poor
Wed 09:00 1.12 · high 3.43 · good 29.60 · good Poor
Wed 10:00 1.12 · high 2.85 · good 29.50 · good Poor
Wed 11:00 1.12 · high 2.02 · good 29.50 · good Poor
Wed 12:00 1.12 · high 0.67 · good 29.50 · good Poor
Wed 13:00 1.12 · high 0.86 · good 29.50 · good Poor
Wed 14:00 1.12 · high 1.66 · good 29.40 · good Poor
Wed 15:00 1.12 · high 3.44 · good 29.40 · good Poor
Wed 16:00 1.12 · high 3.84 · good 29.40 · good Poor
Wed 17:00 1.14 · high 2.95 · good 29.40 · good Poor
Wed 18:00 1.14 · high 2.51 · good 29.40 · good Poor
Wed 19:00 1.14 · high 2.66 · good 29.40 · good Poor
Wed 20:00 1.16 · high 3.26 · good 29.40 · good Poor
Wed 21:00 1.16 · high 2.73 · good 29.40 · good Poor
Wed 22:00 1.20 · high 2.77 · good 29.40 · good Poor
Wed 23:00 1.24 · high 4.46 · good 29.40 · good Poor
Thu 00:00 1.28 · high 6.91 · high 29.40 · good Poor
Thu 01:00 1.40 · high 8.74 · high 29.40 · good Poor
Thu 02:00 1.50 · high 9.27 · high 29.40 · good Poor
Thu 03:00 1.62 · high 9.90 · high 29.40 · good Poor
Thu 04:00 1.72 · high 10.41 · high 29.40 · good Poor
Thu 05:00 1.84 · high 10.72 · high 29.40 · good Poor
Thu 06:00 1.94 · high 10.22 · high 29.40 · good Poor
Thu 07:00 1.96 · high 10.33 · high 29.40 · good Poor
Thu 08:00 1.98 · high 8.53 · high 29.30 · good Poor
Thu 09:00 2.00 · high 6.77 · high 29.30 · good Poor
Thu 10:00 2.02 · high 6.01 · high 29.30 · good Poor
Thu 11:00 2.02 · high 6.95 · high 29.30 · good Poor
Thu 12:00 2.04 · high 7.04 · high 29.30 · good Poor
Thu 13:00 2.04 · high 6.84 · high 29.30 · good Poor
Thu 14:00 2.06 · high 6.79 · high 29.30 · good Poor
Thu 15:00 2.06 · high 7.22 · high 29.20 · good Poor
Thu 16:00 2.06 · high 7.22 · high 29.20 · good Poor
Thu 17:00 2.06 · high 6.97 · high 29.20 · good Poor
Thu 18:00 2.06 · high 5.17 · good 29.20 · good Poor
Thu 19:00 2.06 · high 3.85 · good 29.20 · good Poor
Thu 20:00 2.06 · high 6.31 · high 29.20 · good Poor
Thu 21:00 2.06 · high 5.15 · good 29.20 · good Poor
Thu 22:00 2.02 · high 7.83 · high 29.20 · good Poor
Thu 23:00 2.00 · high 8.17 · high 29.20 · good Poor
Fri 00:00 1.96 · high 8.00 · high 29.20 · good Poor
Fri 01:00 1.94 · high 8.44 · high 29.20 · good Poor
Fri 02:00 1.94 · high 8.66 · high 29.20 · good Poor
Fri 03:00 1.92 · high 8.41 · high 29.20 · good Poor
Fri 04:00 1.88 · high 7.76 · high 29.30 · good Poor
Fri 05:00 1.86 · high 7.44 · high 29.30 · good Poor
Fri 06:00 1.82 · high 6.95 · high 29.30 · good Poor
Fri 07:00 1.80 · high 6.73 · high 29.30 · good Poor
Fri 08:00 1.76 · high 5.59 · high 29.30 · good Fair
Fri 09:00 1.74 · high 5.08 · good 29.20 · good Poor
Fri 10:00 1.70 · high 4.80 · good 29.20 · good Poor
Fri 11:00 1.68 · high 4.73 · good 29.20 · good Poor
Fri 12:00 1.64 · high 4.64 · good 29.20 · good Poor
Fri 13:00 1.62 · high 5.33 · good 29.20 · good Poor
Fri 14:00 1.60 · high 5.46 · high 29.20 · good Poor
Fri 15:00 1.58 · high 4.44 · good 29.20 · good Poor
Fri 16:00 1.56 · high 3.52 · good 29.20 · good Poor
Fri 17:00 1.56 · high 2.30 · good 29.20 · good Poor
Fri 18:00 1.54 · high 3.38 · good 29.20 · good Poor
Fri 19:00 1.52 · high 2.23 · good 29.20 · good Poor
Fri 20:00 1.50 · high 2.19 · good 29.20 · good Poor
Fri 21:00 1.48 · high 3.54 · good 29.20 · good Poor
Fri 22:00 1.46 · high 4.68 · good 29.20 · good Poor
Fri 23:00 1.44 · high 6.66 · high 29.20 · good Poor
Sat 00:00 1.42 · high 3.58 · good 29.20 · good Poor