Surf Forecasts:
Boat Basin Lefts surf forecast from 1 Sep 2026:
- Best quality surf: Sunday 6 Sep, 10PM (local time) - 5ft (1.6m), 10s period, WNW swell with glassy winds.
- Most powerful swell: Friday 4 Sep, 7AM (local time) - 8ft (2.4m), 9s period, W swell with 992 kJ wave energy.
- Next surfable swell (1★+): Sunday 6 Sep, 1PM (local time) - 4.5ft (1.4m), 9s period with WNW 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 (Sep 06) at 1PM. The primary swell is predicted to be 1.4m and 9s period. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Boat Basin Lefts in the next 16 days are 2.4m 9s and forecast to arrive on Friday (Sep 04) at 7AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.8m 6s period and expected on Friday (Sep 04) at 1AM.
| Wave Type | Time (ChST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 1PM (Sun 6th Sep) | 4.5ft (1.4m) 9s |
| Best Surf | 10PM (Sun 6th Sep) | 5ft (1.6m) 10s |
| Most Powerful | 7AM (Fri 4th Sep) | 8ft (2.4m) 9s |
Table - best surf conditions forecast for Boat Basin Lefts over the next 16 days.
The Lowdown
G’day, Rusty here. Let’s break down what’s coming over the next 16 days.
First few days are a total loss. Wednesday 2nd and Thursday 3rd are small and choppy with cross-onshore wind and poor surf. Friday 4th and Saturday 5th get a bump to 2.3m west swell, but the wind is howling cross-shore, making it lumpy and no good.
Sunday 6th afternoon the wind goes glassy and we get a clean 1.4m WNW swell, period 10 seconds, combined energy of 393 – moderate. Still small, but the surface is clean for the first time.
The real standout is Monday 7th. Monday morning is glassy with a 1.6m WNW swell, period 10 seconds, combined energy 581. Then Monday afternoon at Boat Basin Lefts (reef) is the pick: offshore SSE wind at 5 km/h, swell rises to 1.9m from the WNW, period 11 seconds, combined energy 805 – strong energy. Clean, lined-up surf on a reef with west swell. Crowds are possible. This is the one.
Tuesday 8th holds size at 2.0m WNW but cross-shore wind drops the quality. Still okay, but not as good.
From Wednesday 9th through the next week, swell stays consistent at 2.0m to 2.5m from the west with 11-second periods. Combined energy climbs from 909 to 1591 – strong stuff. Wind is often cross-offshore, keeping it fairly clean. Sunday 13th afternoon hits 3.0m WNW with period 12 seconds and combined energy of 2861 – very strong, but cross-shore wind makes it lumpy. Experts only.
Late in the window, Wednesday 16th morning looks clean with a cross-offshore breeze and 1.9m west swell. Thursday 17th morning is the last good one – clear skies, light offshore easterly, 1.3m west swell, period 10 seconds, combined energy 502, and very clean.
Water temp is about average for this time of year.
Best call: Monday 7th afternoon. Don’t miss it.
Rusty.
Short Range ForecastHeavy rain (total 33mm), heaviest during Thu afternoon. Warm (max 28°C on Wed morning, min 26°C on Wed night). Winds increasing (light winds from the SSW on Tue night, fresh winds from the WSW by Thu afternoon). | Days 5-7 Weather SummaryHeavy rain (total 36mm), heaviest during Fri night. Warm (max 29°C on Mon morning, min 27°C on Fri night). Wind will be generally light. | ||||||||||||||||||
Wednesday 2 | Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | ||||||||||||||
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) | W 9 | W 9 | W 9 | W 8 | WNW 9 | WNW 12 | WNW 11 | W 9 | WNW 9 | W 9 | W 9 | W 9 | W 9 | WNW 8 | WNW 10 | WNW 10 | WNW 10 | WNW 11 | WNW 11 |
Wave Graph  | |||||||||||||||||||
 kJ | 306 | 264 | 298 | 265 | 249 | 560 | 460 | 874 | 308 | 600 | 670 | 533 | 363 | 252 | 378 | 555 | 566 | 798 | 966 |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross | cross | cross-on | cross-on | on | cross-on | glassy | glassy | glassy | off | cross-off |
High Tide | 10:06PM0.89m | 11:32AM0.79m | 10:34PM0.89m | 12:49PM0.76m | 11:08PM0.88m | 2:25PM0.75m | 11:51PM0.87m | 4:09PM0.77m | 00:49AM0.85m | 5:24PM0.81m | 2:06AM0.84m | 6:12PM0.84m | 3:32AM0.84m | ||||||
Low Tide | 5:00AM0.25m | 4:48PM0.54m | 5:51AM0.21m | 5:32PM0.62m | 6:50AM0.18m | 6:28PM0.68m | 7:58AM0.15m | 7:54PM0.72m | 9:09AM0.13m | 9:37PM0.73m | 10:17AM0.12m | 10:58PM0.70m | |||||||
 |  | | | |  | | | | | | | |  | |  |  | | | |
 | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — |
 | — | — | 6:31 | — | — | 6:30 | — | — | 6:30 | — | — | 6:30 | — | — | 6:29 | — | — | 6:28 | — |
mm | 6 | 2 | 4 | 7 | 1 | 7 | 4 | 1 | 1 | 16 | 3 | 11 | 6 | — | — | — | — | — | — |
Temp °C | 27 | 28 | 28 | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 27 | 29 | 29 | 27 |
Feels °C | 31 | 30 | 32 | 31 | 30 | 27 | 29 | 28 | 29 | 30 | 30 | 31 | 32 | 32 | 33 | 31 | 33 | 33 | 31 |
Swell 1 Height (m) Direction Period (s) | W 9 | W 9 | W 9 | W 8 | WNW 9 | WNW 12 | WNW 11 | SE 8 | WNW 9 | SE 8 | W 9 | W 9 | W 9 | WNW 8 | WNW 10 | WNW 10 | WNW 10 | WNW 11 | WNW 11 |
| kJ | 306 | 264 | 298 | 265 | 249 | 560 | 460 | 15 | 308 | 17 | 670 | 533 | 363 | 252 | 378 | 555 | 566 | 798 | 966 |
Swell 2 Height (m) Direction Period (s) | NE 10 | NE 9 | NE 9 | NE 10 | NE 10 | NE 9 | NE 9 | NE 8 | SE 8 | ESE 11 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 9 | SE 9 | SE 9 |
| kJ | 47 | 43 | 41 | 46 | 44 | 41 | 28 | 11 | 16 | 11 | 26 | 48 | 60 | 59 | 58 | 45 | 30 | 21 | 29 |
Swell 3 Height (m) Direction Period (s) | E 10 | S 5 | E 10 | SE 9 | NW 13 | ESE 9 | SE 8 | E 9 | NE 9 | E 9 | SSE 8 | ENE 9 | ENE 8 | ENE 9 | ENE 9 | ENE 8 | ENE 9 | ENE 8 | ENE 8 |
| kJ | 8 | 5 | 8 | 13 | 46 | 8 | 18 | 6 | 22 | 7 | 6 | 16 | 14 | 7 | 15 | 14 | 15 | 7 | 7 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | WSW 7 | SW 8 | SW 6 | W 9 | SW 7 | W 9 | — | — | — | WSW 8 | SW 6 | — | — | — | S 7 |
| kJ | — | — | — | — | 70 | 143 | 263 | 874 | 237 | 600 | — | — | — | 74 | 32 | — | — | — | 4 |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 11 | 11 | 11 | 11 | 1905 | 229 | 1304 | 231 | 1958 | 2055 | 16 | 11 | 11 | 11 | 0 | 0 | 0 | 0 | 0 |
Best forecast wave conditions in Guam | |||||||||||||||||||
Best forecast wave conditions in Guam | |||||||||||||||||||
Header Global | |||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
FREE! Surf-Forecast.com widget for your website
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.
Nearest