
Surf Forecasts:
Boat Basin Lefts surf forecast from 18 Jul 2026:
- Best quality surf: Thursday 23 Jul, 10PM (local time) - 6ft (1.9m), 7s period, NE swell with cross-offshore winds.
- Most powerful swell: Friday 24 Jul, 1AM (local time) - 6ft (1.9m), 8s period, ENE swell with 480 kJ wave energy.
- Next surfable swell (1★+): Thursday 23 Jul, 10PM (local time) - 6ft (1.9m), 7s period with NE 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 Thursday (Jul 23) at 10PM. The primary swell is predicted to be 1.9m and 7s period. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Boat Basin Lefts in the next 16 days are 1.9m 8s and forecast to arrive on Friday (Jul 24) at 1AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 4.0m 9s period and expected on Friday (Jul 24) at 4PM.
| Wave Type | Time (ChST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 10PM (Thu 23rd Jul) | 6ft (1.9m) 7s |
| Best Surf | 10PM (Thu 23rd Jul) | 6ft (1.9m) 7s |
| Most Powerful | 1AM (Fri 24th Jul) | 6ft (1.9m) 8s |
Table - best surf conditions forecast for Boat Basin Lefts over the next 16 days.
The Lowdown
Alright folks, Rusty here, looking at the next 16 days for Boat Basin Lefts. Gotta be straight with you – this stretch is a real struggle. We’ve got a long, dry gap before anything remotely worth a mention. Right now, from Sunday July 19 through to maybe Wednesday July 22, the swell is tiny – we’re talking 1.3 ft to 1.6 ft, mostly from the east with short period around 9 seconds. Wind is cross‑off or light offshore at times, but even with clean conditions, there’s no power. Combined energy is sitting weak, around 27 to 46 – just not enough to push a wave. It’s a flat spell.
Things try to kick off a little on Thursday July 23 morning: we see a pulse of 3.6 ft from the ENE, period only 7 seconds, so it’s short and weak, energy just 123 – still poor. That afternoon it jumps to 5.2 ft from the NE, but period drops to 6 seconds, and the wind goes cross. That’s a messy, choppy combo, definitely not for paddling. If you’re into kite surfing, that afternoon might look more interesting, but for a surfboard? Forget it.
Then another dry stretch Friday through Sunday – gusty south winds, tiny waves, nothing happening.
Now, the first faint glimmer shows up Monday July 27 morning: we get 3 ft from the WNW, period 9 seconds, combined energy 151 – still ordinary but at least you can paddle. Wind is light cross‑off, so the surface is clean. Still, it’s marginal at best – a 1 out of 10 kind of day.
The best on offer across the whole 16-day window? That would be Wednesday July 29 afternoon. We’ve got a 4.3 ft swell from the NNW with a longer period of 13 seconds – that’s proper groundswell, which will hold shape better on a reef like this. Combined energy is moderate at 529. The bad news is wind is light cross‑onshore, which puts a slight wrinkle on the face. Still, if you’re desperate, this is the pick. Keep in mind it’s a full week and a half away, so there’s some uncertainty. And this spot can get crowds sometimes,
Short Range ForecastLight rain (total 5mm), mostly falling on Sat night. Warm (max 29°C on Sun morning, min 27°C on Sat night). Wind will be generally light. | Days 5-7 Weather SummaryHeavy rain (total 62mm), heaviest during Fri afternoon. Warm (max 29°C on Wed morning, min 26°C on Thu night). Winds increasing (light winds from the NE on Thu night, strong winds from the S by Fri morning). | ||||||||||||||||||
Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | ||||||||||||||
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) | E 9 | E 9 | E 9 | E 9 | E 10 | E 9 | E 9 | ENE 9 | ENE 9 | ENE 9 | ENE 9 | ENE 9 | E 5 | ENE 7 | NE 6 | ENE 8 | NNE 7 | ENE 9 | ENE 9 |
Wave Graph | |||||||||||||||||||
41 | 41 | 41 | 42 | 46 | 44 | 42 | 28 | 27 | 27 | 27 | 46 | 9 | 99 | 201 | 480 | 77 | 8 | 8 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-off | cross-off | cross-off | off | off | glassy | cross-off | cross-off | cross | cross-off | cross | cross | cross-off | cross | cross | cross-off | cross-off | cross-off |
High Tide | 11:30PM0.93m | 10:51AM0.78m | 11:58PM0.92m | 12:04PM0.72m | 00:26AM0.90m | 1:30PM0.68m | 00:54AM0.88m | 3:12PM0.67m | 1:23AM0.85m | 5:00PM0.69m | 1:58AM0.83m | 6:20PM0.73m | 2:40AM0.82m | ||||||
Low Tide | 5:36AM0.49m | 5:13PM0.31m | 6:32AM0.43m | 5:50PM0.42m | 7:27AM0.37m | 6:26PM0.53m | 8:22AM0.32m | 7:07PM0.61m | 9:16AM0.28m | 8:04PM0.67m | 10:07AM0.24m | 9:26PM0.70m | |||||||
— | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:03 | — | — | 6:03 | — | — | 6:03 | — | — | |
— | — | 6:52 | — | — | 6:51 | — | — | 6:51 | — | — | 6:51 | — | — | 6:51 | — | — | 6:51 | — | |
mm | 2 | 1 | — | — | — | 2 | — | — | — | — | 1 | 1 | 9 | 6 | 3 | 19 | 8 | 15 | 19 |
Temp °C | 28 | 29 | 29 | 27 | 29 | 28 | 27 | 29 | 29 | 27 | 29 | 29 | 27 | 28 | 28 | 27 | 27 | 26 | 27 |
Feels °C | 32 | 32 | 32 | 31 | 31 | 30 | 31 | 32 | 32 | 31 | 32 | 32 | 30 | 30 | 31 | 31 | 26 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | WSW 6 | WSW 6 | WSW 6 | WSW 7 | SW 7 | SW 7 | SW 7 | WSW 7 | WSW 7 | WSW 7 | WSW 7 | WSW 7 | SW 7 | SE 9 | SE 9 | ENE 8 | NNE 7 | SE 10 | SE 10 |
41 | 30 | 23 | 40 | 69 | 73 | 53 | 43 | 33 | 33 | 35 | 33 | 23 | 53 | 54 | 480 | 77 | 27 | 48 | |
Swell 2 Height (m) Direction Period (s) | E 9 | E 9 | E 9 | E 9 | E 10 | E 9 | SSE 9 | ENE 9 | SE 10 | SE 11 | SE 10 | ENE 9 | SE 10 | SW 7 | SW 7 | SSW 8 | SE 10 | SE 14 | SE 14 |
41 | 41 | 41 | 42 | 46 | 44 | 47 | 28 | 48 | 57 | 64 | 46 | 47 | 24 | 23 | 67 | 28 | 32 | 8 | |
Swell 3 Height (m) Direction Period (s) | S 6 | S 6 | S 5 | SE 8 | SE 8 | SE 9 | E 9 | SE 9 | ENE 9 | ENE 9 | ENE 9 | SE 10 | E 5 | ENE 8 | S 7 | SW 8 | SE 14 | ENE 9 | ENE 9 |
7 | 11 | 9 | 16 | 15 | 21 | 42 | 21 | 27 | 27 | 27 | 61 | 9 | 24 | 16 | 15 | 33 | 8 | 8 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | ENE 3 | ENE 3 | ENE 5 | NNE 3 | ENE 7 | NE 6 | N 5 | SW 8 | SW 9 | SW 9 |
— | — | — | — | — | — | — | — | — | 1 | 2 | 10 | 4 | 99 | 201 | 113 | 789 | 2441 | 1556 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 11 | 0 | 0 | 0 | 0 | 0 | 0 | 2075 | 2458 | 2253 | 26 | 2256 | 2200 | 2253 | 2100 | 1885 | 2069 | 2075 | 2064 |
Best forecast wave conditions in Guam | |||||||||||||||||||
Best forecast wave conditions in Guam | |||||||||||||||||||
Header Global | |||||||||||||||||||
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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.










