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Boat Basin Lefts surfForecast / Guam / Guam
12 Day Weather and Surf, issued 3 pm Thursday 16 Oct 2025 ChST
Best Forecast Surf Conditions for Boat Basin Lefts this week:
The surf forecast for Boat Basin Lefts over the next 12 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Oct 21) at 1PM. The primary swell is predicted to be 1.0m and 12s period with a secondary swell of 0.9m and 8s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Boat Basin Lefts in the next 12 days are 1.0m 12s and forecast to arrive on Tuesday (Oct 21) at 4AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.5m 8s period and expected on Wednesday (Oct 22) at 10PM.
| Wave Type | Time (ChST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 1PM (Tue 21st Oct) | 3.5ft (1.0m) 12s |
| Best Surf | 1PM (Tue 21st Oct) | 3.5ft (1.0m) 12s |
| Most Powerful | 4AM (Tue 21st Oct) | 3.5ft (1.0m) 12s |
Table - best surf conditions forecast for Boat Basin Lefts over the next 12 days.
Short Range Forecast Moderate rain (total 11mm), heaviest on Sat morning. Warm (max 29°C on Fri morning, min 28°C on Thu afternoon). Wind will be generally light. | Days 3-6 Weather Summary Moderate rain (total 17mm), heaviest on Mon night. Warm (max 29°C on Sun afternoon, min 27°C on Sun night). Wind will be generally light. | ||||||||||||||||||||||
Thu 16 | Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | |||||||||||||||||
| PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | |||
Rating (10 max) | |||||||||||||||||||||||
Swell Height Map |  |  |  |  |  |  |  |  | |||||||||||||||
| Wave Height (m) & direction (?) | |||||||||||||||||||||||
| Period(s) (?) | 13 | 7 | 7 | 7 | 12 | 8 | 8 | 8 | 7 | 7 | 7 | 8 | 8 | 12 | 12 | 12 | 11 | 10 | 10 | 10 | 9 | ||
Wave (?)Graph  | |||||||||||||||||||||||
 kJ (?) | 121 | 107 | 203 | 181 | 220 | 235 | 202 | 280 | 245 | 171 | 172 | 142 | 125 | 236 | 293 | 237 | 183 | 132 | 132 | 61 | 157 | ||
Wind (km/h) | |||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | off | off | off | off | off | off | ||
High Tide / height (m) | 5:04PM 0.84 | 3:44AM 0.73 | 5:34PM 0.85 | 5:04AM 0.75 | 5:59PM 0.86 | 6:09AM 0.78 | 6:21PM 0.86 | 7:04AM 0.81 | 6:42PM 0.86 | 7:53AM 0.84 | 7:02PM 0.85 | 8:38AM 0.85 | 7:24PM 0.84 | 9:23AM 0.86 | |||||||||
Low Tide / height (m) | 11:00PM 0.58 | 10:34AM 0.31 | 11:43PM 0.50 | 11:24AM 0.36 | 12:19AM 0.43 | 12:09PM 0.41 | 12:50AM 0.35 | 12:50PM 0.46 | 1:20AM 0.28 | 1:28PM 0.51 | 1:50AM 0.22 | 2:05PM 0.55 | 2:20AM 0.17 | ||||||||||
Thu 16 | Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | |||||||||||||||||
| Sunrise | - | - | 6:11 | - | - | 6:11 | - | - | 6:11 | - | - | 6:11 | - | - | 6:11 | - | - | 6:11 | - | - | 6:11 | ||
| Sunset | 6:00 | - | - | 6:00 | - | - | 6:00 | - | - | 6:00 | - | - | 5:59 | - | - | 5:58 | - | - | 5:58 | - | - | ||
 |  |  | |  | | | | | | | | | | | | | | |  |  | |||
Rain (mm) | 1 | - | - | - | 2 | 2 | 3 | 1 | 2 | 1 | - | 2 | 2 | 6 | 2 | 1 | 1 | 2 | 4 | 10 | - | ||
| Temp. °C | 28 | 28 | 29 | 29 | 28 | 29 | 29 | 28 | 29 | 29 | 28 | 29 | 29 | 27 | 29 | 28 | 28 | 29 | 30 | 28 | 29 | ||
| Feels °C (?) | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 29 | 30 | 30 | 30 | 31 | 31 | 29 | 31 | 30 | 30 | 32 | 33 | 30 | 31 | ||
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Live Wave Height (m)
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Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
Recent Eyeball Surf Reports for Guam
Continuing clean conditions at Boat Basin Lefts (light winds from the E at Tamuning 3 km from Boat Basin Lefts). 1.1m 6s windswell from the E with a 0.4m 12s groundswell from the NNE. 2 swells combining to make bigger set waves.
1 h 33 min ago
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Boat Basin Lefts surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
Information about the Boat Basin Lefts Surf forecast
The above surf forecast table for Boat Basin Lefts provides essential information for determining whether the surfing conditions will be good over the next 12 days. A general guide to surfing at Boat Basin Lefts can be found by selecting the local surf guide option on the grey menu. Our Boat Basin Lefts surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Boat Basin Lefts) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Boat Basin Lefts may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Boat Basin Lefts is 1 km (1 miles) from Agana. If you plan a holiday in Guam, look for hotels and other accommodation in Agana. Agana has rooms for a wide range of budgets as well as car hire and transport links.
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