Reading the wind: the conditions that make or break an eFoil session

Kitesurfers and wing foilers chase wind. eFoilers avoid it. The motor does the work, so the ideal session is the one a windsurfer would call a wasted day: no wind, no swell, water like glass. Learning to read a forecast for calm rather than for wind is the single most useful skill after learning to fly.

Knots, and what they mean on a foil

Marine forecasts and the Atlas both use knots. One knot is about 1.85 km/h or 1.15 mph. Here is how the bands feel from a foil board:

Wind	What the water does	Who it suits
0–6 kt	Glass or a faint ripple.	Everyone. Learn here, film here.
6–12 kt	Small ripples, occasional chop in open water.	Comfortable for anyone who can already fly.
12–18 kt	Steady chop; whitecaps start above 15.	Experienced riders in sheltered water.
18+ kt	Whitecaps, gusts, real chop.	Skip it, or find a bay in the lee.

Two things make the numbers worse than they look. Fetch — the distance wind has blown across open water — turns 12 knots into flat water in a lagoon and into chop on an exposed beach. And gusts: a forecast of 10 knots gusting 20 is a 20-knot day for balance purposes, because it is the gust that knocks you off the foil. The Atlas shows gusts next to the average for exactly this reason.

Direction matters more than speed

Offshore wind (blowing from land out to sea) is the dangerous one. The water near the beach looks deceptively flat because the wind hasn't had room to build chop, but it pushes you — and a dead battery — away from shore. Never ride offshore wind alone or far out.

Onshore wind builds chop against the beach but pushes you home. Uncomfortable, safe.

Cross-shore is the compromise most spots live with: chop, but a straight line back to the beach at any point.

The daily cycle: why mornings are glass

On almost every coast in the Atlas the wind is thermal. The land heats faster than the sea, warm air rises, and a sea breeze rushes in to replace it — starting late morning, peaking mid-afternoon, dying at dusk. The result is the pattern our spot pages describe again and again: glassy mornings, windy afternoons.

Some places have a named version of it. On Lake Garda the Pelèr blows from the north in the morning and the Ora from the south in the afternoon, with a calm window between. At Alaçatı the Imbat arrives after lunch like clockwork from May to October. At Tarifa the Levante and Poniente are funnelled through the Strait of Gibraltar and can blow at 15 to 25 knots for days — which is why the lagoon side of the beach matters so much there.

The practical rule: for calm water, book the first session of the day.

Waves and swell

Wave height on the Atlas comes from the same forecast model as the wind, shown for coastal spots.

• Under 0.3 m — flat for practical purposes.
• 0.3–0.6 m — manageable once you can fly steadily; the foil actually smooths small swell.
• Over 1 m — a specialist game (foil surfing) rather than a cruising session.

Swell period is the gap between waves in seconds. Long-period swell (10 seconds or more) is smooth and rideable; short-period wind chop of the same height is far rougher. Sheltered bays such as Port de Pollença, the Bay of Cannes and Fornells are on the Atlas precisely because they filter swell out.

Water temperature

The forecast for coastal spots includes sea-surface temperature. Below about 18 °C you will want a full wetsuit for a first session — you spend a lot of the first half hour in the water — and below 14 °C a thicker one plus boots. Above 24 °C a rash vest is enough.

The rideability score

Every spot on the Atlas carries a rideability score from 0 to 10, where 10 is glass. It is computed every two hours from the same forecast you see on the spot page: wind speed is the backbone, gusts above the average are penalised, and at coastal spots wave height is folded in so that light wind over leftover swell cannot score well. The bands are Glassy (8.5+), Good (7–8.4), Rideable (5–6.9), Choppy (3–4.9) and Blown out (below 3). From the hourly scores we also pick the day's best window — the longest stretch scoring 7 or more between 06:00 and 20:00 local time — so "Best window today: 06:00–10:00" on a spot page means exactly that. Treat it as a first read, not a verdict: it knows nothing about a bay's shelter or a local thermal that arrives early.

How to use the Atlas

• Every spot page has a Conditions panel led by the rideability score and the best window today, with wind, gusts, air and water temperature, wave height and swell beneath it, the next 12 hours coloured by score, and a 7-day outlook. It refreshes every two hours.
• The map has a rideability filter: the "Glassy now (8+)" preset shows only spots scoring 8 or more at this moment, and the wind and wave sliders sit beside it for finer control.
• Pins on the map show the current wind speed and direction, so you can scan a whole coastline for the calm bay.

A pre-session checklist

1. Average wind under 12 knots, gusts under 15.
2. Wind not offshore — or if it is, stay inside the bay and near the operator.
3. Wave height under 0.5 m at coastal spots.
4. Sunset time and battery time: don't start a session you can't finish in daylight.
5. Somebody knows where you are, and the local rules on distance from swimmers are in your head — see the regulations guide.