Surf Forecasts:
Boat Basin Lefts surf forecast from 17 Oct 2026:
- Best quality surf: Sunday 18 Oct, 4AM (local time) - 25ft (7.5m), 14s period, ENE swell with cross-onshore winds.
- Most powerful swell: Sunday 18 Oct, 7AM (local time) - 30ft (9.0m), 13s period, E swell with 27,487 kJ wave energy.
- Next surfable swell (1★+): Sunday 18 Oct, 4AM (local time) - 25ft (7.5m), 14s period with ENE swell.
Best Forecast Surf Conditions for Boat Basin Lefts this week:
The surf forecast for Boat Basin Lefts over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Sunday (Oct 18) at 4AM. The primary swell is predicted to be 7.5m and 14s period with a secondary swell of 6.0m and 13s. The wind is predicted to be cross-onshore as the swell arrives.
The most powerful waves expected at Boat Basin Lefts in the next 16 days are 9.0m 13s and forecast to arrive on Sunday (Oct 18) at 7AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 10.5m 13s period and expected on Sunday (Oct 18) at 10AM.
| Wave Type | Time (ChST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 4AM (Sun 18th Oct) | 25ft (7.5m) 14s |
| Best Surf | 4AM (Sun 18th Oct) | 25ft (7.5m) 14s |
| Most Powerful | 7AM (Sun 18th Oct) | 30ft (9.0m) 13s |
Table - best surf conditions forecast for Boat Basin Lefts over the next 16 days.
Short Range ForecastHeavy rain (total 156mm), heaviest during Sun morning. Warm (max 28°C on Sat morning, min 26°C on Sat morning). Winds increasing (fresh winds from the N on Sat morning, stormy winds from the SSE by Sun morning). | Days 4-6 Weather SummaryModerate rain (total 19mm), heaviest on Tue afternoon. Warm (max 29°C on Wed morning, min 26°C on Wed night). Wind will be generally light. | ||||||||||||||||||||
Saturday 17 | Sunday 18 | Monday 19 | Tuesday 20 | Wednesday 21 | Thursday 22 | Friday 23 | |||||||||||||||
AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map |  |  |  |  |  |  |  | ||||||||||||||
Wave Height (m) Direction Period (s) | ENE 9 | ENE 11 | E 13 | NE 9 | ENE 9 | NE 10 | ENE 9 | W 11 | W 11 | WNW 11 | W 11 | WNW 12 | WNW 12 | WNW 11 | WNW 12 | WNW 12 | WNW 13 | WNW 13 | WNW 14 | WNW 15 | WNW 15 |
Wave Graph  | |||||||||||||||||||||
 kJ | 188 | 862 | 7161 | 468 | 148 | 92 | 73 | 118 | 86 | 202 | 313 | 425 | 478 | 446 | 540 | 452 | 643 | 732 | 1259 | 1377 | 1578 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | off | off | cross-off | cross-off | cross | cross | cross | cross | cross | cross-off | cross |
High Tide | 1:39PM0.77m | 10:16PM0.76m | 2:49PM0.77m | 11:01PM0.73m | 3:46PM0.78m | 00:16AM0.70m | 4:25PM0.80m | 2:04AM0.68m | 4:53PM0.82m | 3:43AM0.70m | 5:16PM0.84m | 5:02AM0.74m | 5:37PM0.86m | ||||||||
Low Tide | 6:07PM0.69m | 6:27AM0.24m | 7:30PM0.69m | 7:25AM0.27m | 9:06PM0.67m | 8:25AM0.30m | 10:12PM0.63m | 9:24AM0.33m | 10:55PM0.57m | 10:18AM0.35m | 11:30PM0.48m | 11:08AM0.39m | 00:04AM0.39m | ||||||||
 | |  | | |  | |  | | | | | |  | | | | |  | | | |
 | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — |
 | — | 6:00 | — | — | 6:00 | — | — | 6:00 | — | — | 5:59 | — | — | 5:58 | — | — | 5:58 | — | — | 5:57 | — |
mm | 21 | 19 | 25 | 61 | 6 | 9 | 6 | 6 | 3 | 2 | 5 | 6 | 1 | — | 4 | — | — | 1 | 1 | 2 | 2 |
Temp °C | 28 | 27 | 27 | 26 | 27 | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 29 | 29 | 27 | 28 | 28 | 27 | 28 | 28 | 27 |
Feels °C | 28 | 26 | 24 | 12 | 22 | 23 | 25 | 25 | 27 | 28 | 29 | 30 | 31 | 31 | 30 | 31 | 30 | 30 | 30 | 30 | 30 |
Swell 1 Height (m) Direction Period (s) | ENE 9 | ENE 11 | E 13 | NE 9 | ENE 9 | NE 10 | ENE 9 | WSW 10 | WSW 10 | WSW 10 | W 11 | SW 9 | SW 9 | WNW 11 | WNW 12 | WNW 12 | WNW 13 | WNW 13 | WNW 14 | WNW 15 | WNW 15 |
| kJ | 188 | 862 | 7161 | 468 | 148 | 92 | 73 | 600 | 279 | 205 | 313 | 526 | 269 | 446 | 540 | 452 | 643 | 732 | 1259 | 1377 | 1578 |
Swell 2 Height (m) Direction Period (s) | SE 9 | SE 10 | — | — | — | W 10 | NNE 11 | W 11 | ENE 9 | WNW 11 | WSW 9 | WNW 12 | WNW 12 | SW 8 | WSW 8 | ENE 8 | ENE 8 | ENE 8 | SE 9 | ENE 9 | ENE 9 |
| kJ | 14 | 14 | — | — | — | 87 | 22 | 118 | 68 | 202 | 156 | 425 | 478 | 191 | 120 | 111 | 150 | 150 | 14 | 207 | 207 |
Swell 3 Height (m) Direction Period (s) | SW 5 | — | — | — | — | — | NNE 11 | ENE 9 | W 11 | ENE 9 | ENE 9 | ENE 9 | ENE 8 | ENE 8 | ENE 8 | WSW 8 | WSW 8 | WSW 8 | N 11 | SE 9 | WSW 8 |
| kJ | 1 | — | — | — | — | — | 11 | 73 | 86 | 65 | 70 | 65 | 90 | 90 | 90 | 101 | 75 | 42 | 9 | 14 | 26 |
Wind waves Height (m) Direction Period (s) | N 4 | NNE 6 | NNE 8 | SE 13 | S 11 | S 10 | S 9 | S 9 | S 9 | S 8 | S 8 | SSE 7 | — | — | — | — | — | — | ENE 9 | — | — |
| kJ | 39 | 275 | 1473 | 32963 | 12188 | 4831 | 2424 | 1391 | 1138 | 699 | 476 | 88 | — | — | — | — | — | — | 211 | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1290 | 2069 | 1290 | 1290 | 1290 | 1836 | 1836 | 2064 | 1836 | 1836 | 0 | 0 | 0 | 0 | 1836 | 20 | 1864 | 20 | 1290 | 1864 | 20 |
Best forecast wave conditions in Guam | |||||||||||||||||||||
Best forecast wave conditions in Guam | |||||||||||||||||||||
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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 16 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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