“Sports outing” menu: where to go depending on sport and wind

User guide · updated 19.10.2026

Kite, wing, windsurf, wake, paddle, jet ski: the right water at the right time, and where to hire or learn.

What this menu is for

The Navleman menu, with the “Sports outing” tile circled. — Menu, then the “Sports outing” tile.

Two sections: maps by sport, calculated from the forecast wind and the shape of the lake, and rental spots — schools, clubs, hire companies and shops.

How to use it

Open the menu

Tap Menu, bottom right, then the menu's tile. At the top: 📖 User guide for this menu (this page) and ↺ Reset maps, which switches everything off at once.

The open menu, with its list of map layers and a checkbox in front of each. — The open menu: one row per map layer.

Turn on a map layer

Tick a map layer's box to lay it over the base map; untick it to remove it. The arrow at the right of the row opens its info note: what the layer shows, its colour key, its source and what it doesn't tell you. An OFFLINE label marks a layer built into the app, which works without signal.

One map per sport at a time: “Kite and sailing — windy areas” for wind, “Wakeboard — flat water” or “Shelter” for calm water (wake, paddle, water-skiing). Then drag the time slider: you can watch the morning’s flat water close up by midday.

Why checkboxes? So that only what's useful right now goes on the map: ten layers switched on together become unreadable.

Two map layers ticked in the list; the arrow at the right of a row opens its info note. — Tick the box; the arrow on the right opens the layer's info note.

Reading the map

Rental spots are shown as points: here the paddle, kayak and board schools and hire companies around the Grand-Lac.

The map of the Grand-Lac with the blue icons of paddle hire companies. — Paddle, kayak and board spots.

Tap a point: the pop-up

The name, preceded by the layer's icon.
Facilities — harbour name (expandable): when the place bears a harbour's name, that harbour's facilities confirmed by an official source (slipway, crane, pump-out, fuel) and the harbour master's office phone number.
The practical note when known: access from the beach or the nearby harbour, season, booking.
A row of links: the website ↗, the phone number (one tap calls) and “View on Google Maps ↗”.
Sources and position (expandable): where the place comes from and how its position was obtained — official address, OpenStreetMap or read off the map.
Set course makes it your destination in “Where to?”; Start from here, your starting point.

The pop-up for a paddle hire company: website, phone, Google Maps, sources and position, Set course and Start from here. — A hire company's pop-up: website, phone, Google Maps.

How the data is cross-checked

The maps by sport use the same calculation as the waves: for each 50 m grid cell, the forecast wind (ICON-CH1) and the fetch, the stretch of open water the wind travels over before reaching the point.

Wakeboard — flat water: the estimated wave height; green below 10 cm.
Kite and sailing: the wind AND the water ahead — “ideal” at 18 knots or more with over 3 km of open water, “good” at 12 knots or more with over 1,5 km, “light” from 8 to 12 knots.
Shelter: fetch alone — well sheltered below 600 m, sheltered up to 2 km.

The rental spots come from the app's verified files, place by place.

Maps by sport

A synthesis built on what the app already knows: the forecast wind (ICON-CH1), the surface current (Eawag's 3D model) and the shape of the lake. Five readings of the same map — flat water for jet skis, windy areas for kite and sailing, a synthesis for navigation, wave height alone, and shelter for the current wind. You switch on one at a time, as with the fish species.

Each follows the time slider, which appears as soon as one of these layers is on: slide it and the map recalculates hour by hour, without waiting for you to let go. You can watch the morning's flat water close up by midday, and the shelter switch shores when the bise gives way to the joran.

Fetch is the key: the stretch of open water the wind travels over before reaching the point. The app calculates it by tracing back upwind from cell to cell until it hits land. A point 200 m to leeward of a shore is sheltered; the same point with 20 km of lake ahead of it gets a short, uncomfortable chop.

Wave height is an estimate, not a measurement. It uses the Sverdrup-Munk-Bretschneider formula, the one found in coastal engineering manuals for waves raised by the local wind. It knows nothing of residual swell, gusts or the cross chop after a wind shift. The only real wave measurement on Lake Geneva is the LéXPLORE buoy, off Pully, but Eawag only publishes its readings as weekly files, weeks late. So the app doesn't use it, and never displays a height presented as measured.

The drift alert sounds when the current under the boat exceeds 30 cm/s. Like the other alarms, it stays silent before “Let's go”.

🚤 Wakeboard — flat water

Flat-water areas at the time shown: little wind and above all little fetch, so no chop has built up. The time slider drives this layer: drag it and everything is recalculated.

flat water (wave < 10 cm)light chop (10–20 cm)chop (20–35 cm)rough (≥ 35 cm)

Tip. Look for green: flat water, waves under 10 cm.