SnorkelForecast.com

Tumon Bay Snorkel Report Today

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

The skinny

Marginal Report Thu 01:25

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

29.2°C

Max air

31.2°C

Sky

Partly cloudy

41% 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 (36 hours)
  • Tide/current (32 hours)
  • Darkness (23 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

Thu 15:00 – Sun 15:00 (ChST)

Previous day Yesterday Next day Live

Snorkel Score (selected 24h)

Best snorkel score is 0.3 around Fri 13:00; 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 0.7m to 0.72m).

Wind is at or below 5.4m/s in 0/24 sampled hours (range 7.3 to 17.6m/s).

Tides range from 0.35m to 1.13m; 2 of 24 hours are in or near peak slack windows.

72-hour historical overview
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
poor ❌ Limited
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 15:00 0.70 · high 14.50 · high 29.90 · good poor
Thu 16:00 0.70 · high 8.40 · high 29.80 · good poor
Thu 17:00 0.70 · high 7.30 · high 29.80 · good poor
Thu 18:00 0.70 · high 8.20 · high 29.80 · good poor
Thu 19:00 0.70 · high 10.20 · high 29.80 · good poor
Thu 20:00 0.70 · high 11.70 · high 29.80 · good poor
Thu 21:00 0.70 · high 14.10 · high 29.80 · good poor
Thu 22:00 0.70 · high 12.20 · high 29.80 · good poor
Thu 23:00 0.70 · high 13.80 · high 29.90 · good poor
Fri 00:00 0.70 · high 14.20 · high 29.90 · good poor
Fri 01:00 0.70 · high 15.50 · high 29.90 · good poor
Fri 02:00 0.70 · high 15.60 · high 30.00 · good poor
Fri 03:00 0.70 · high 16.80 · high 30.00 · good poor
Fri 04:00 0.70 · high 17.40 · high 30.10 · good poor
Fri 05:00 0.72 · high 17.60 · high 30.10 · good poor
Fri 06:00 0.72 · high 15.70 · high 30.10 · good poor
Fri 07:00 0.72 · high 15.10 · high 30.10 · good poor
Fri 08:00 0.70 · high 14.10 · high 30.10 · good poor
Fri 09:00 0.70 · high 12.90 · high 30.10 · good poor
Fri 10:00 0.70 · high 11.90 · high 30.10 · good poor
Fri 11:00 0.70 · high 14.40 · high 30.00 · good poor
Fri 12:00 0.70 · high 13.00 · high 30.00 · good poor
Fri 13:00 0.70 · high 12.80 · high 29.90 · good poor
Fri 14:00 0.70 · high 13.60 · high 29.90 · good poor
Fri 15:00 0.70 · high 6.00 · high 29.90 · good poor
Fri 16:00 0.72 · high 15.40 · high 29.90 · good poor
Fri 17:00 0.72 · high 10.90 · high 29.90 · good poor
Fri 18:00 0.74 · high 7.70 · high 29.90 · good poor
Fri 19:00 0.76 · high 10.50 · high 29.90 · good poor
Fri 20:00 0.80 · high 11.60 · high 29.90 · good poor
Fri 21:00 0.82 · high 14.50 · high 29.80 · good poor
Fri 22:00 0.84 · high 16.50 · high 29.80 · good poor
Fri 23:00 0.88 · high 17.30 · high 29.90 · good poor
Sat 00:00 0.90 · high 18.70 · high 29.90 · good poor
Sat 01:00 0.94 · high 20.00 · high 29.90 · good poor
Sat 02:00 1.00 · high 21.90 · high 30.00 · good poor
Sat 03:00 1.04 · high 17.30 · high 30.10 · good poor
Sat 04:00 1.10 · high 20.00 · high 30.10 · good poor
Sat 05:00 1.16 · high 23.70 · high 30.20 · good poor
Sat 06:00 1.22 · high 19.40 · high 30.20 · good poor
Sat 07:00 1.28 · high 21.40 · high 30.20 · good poor
Sat 08:00 1.34 · high 20.30 · high 30.20 · good poor
Sat 09:00 1.40 · high 14.20 · high 30.10 · good poor
Sat 10:00 1.44 · high 16.00 · high 30.00 · good poor
Sat 11:00 1.48 · high 15.60 · high 30.00 · good poor
Sat 12:00 1.52 · high 22.20 · high 29.90 · good poor
Sat 13:00 1.54 · high 17.10 · high 29.90 · good poor
Sat 14:00 1.56 · high 18.60 · high 29.90 · good poor
Sat 15:00 1.58 · high 20.40 · high 29.90 · good poor
Sat 16:00 1.64 · high 19.30 · high 29.90 · good poor
Sat 17:00 1.68 · high 22.20 · high 29.90 · good poor
Sat 18:00 1.74 · high 23.80 · high 29.90 · good poor
Sat 19:00 1.80 · high 24.70 · high 29.90 · good poor
Sat 20:00 1.84 · high 26.40 · high 29.90 · good poor
Sat 21:00 1.90 · high 25.10 · high 29.90 · good poor
Sat 22:00 1.96 · high 30.70 · high 29.80 · good poor
Sat 23:00 2.00 · high 30.70 · high 29.80 · good poor
Sun 00:00 2.06 · high 33.40 · high 29.80 · good poor
Sun 01:00 2.12 · high 34.80 · high 29.80 · good poor
Sun 02:00 2.20 · high 36.30 · high 29.80 · good poor
Sun 03:00 2.26 · high 35.00 · high 29.80 · good poor
Sun 04:00 2.32 · high 38.50 · high 29.80 · good poor
Sun 05:00 2.36 · high 35.40 · high 29.80 · good poor
Sun 06:00 2.42 · high 35.20 · high 29.80 · good poor
Sun 07:00 2.58 · high 38.60 · high 29.80 · good poor
Sun 08:00 2.72 · high 38.00 · high 29.80 · good poor
Sun 09:00 2.88 · high 38.50 · high 29.80 · good poor
Sun 10:00 3.04 · high 40.30 · high 29.70 · good poor
Sun 11:00 3.18 · high 43.30 · high 29.70 · good poor
Sun 12:00 3.34 · high 46.70 · high 29.70 · good poor
Sun 13:00 3.54 · high 48.60 · high 29.70 · good poor
Sun 14:00 3.76 · high 51.70 · high 29.70 · good poor