Weather & Sail Brief

For each upcoming sail, Zeil shows the weather forecast for the time you'll be on the water and — closer to the date — an AI-written Sail Brief.

At a glance

Your upcoming sail cards — on your club home and in your Logbook — carry a small weather chip so you can read the expected conditions without opening the sail: a sky glyph (clear, cloudy, or rain), the wind speed with a needle pointing the way the breeze blows, gusts and compass bearing, and the temperature. On tidal waters the chip also shows the next tide event — for example ▲ 2:47p for a coming high water. If a sail is too far out to forecast yet, the chip simply appears closer to the date.

The forecast

Open a reservation to see the full forecast for its time window, including:

• Wind — speed, gusts, and direction, with a small chart beneath it showing how the breeze builds or eases across your window.
• Temperature.
• Precipitation and cloud cover.

Wind is shown in your club's preferred unit (knots, m/s, or mph), set by your administrator.

Once a sail is under way, the forecast doesn't disappear — it covers the rest of your window, from now to the sail's end time, so you can check what the afternoon still has in store. It drops off the page once the sail's end time has passed.

Tide times

If your club sails tidal waters, the forecast also shows the tide schedule for your window — the upcoming high and low waters with their times and heights, like ▲ High 6:14 pm (8.2 ft) · ▼ Low 12:50 am (0 ft). Times are in your club's timezone; heights are in feet for US clubs and meters elsewhere.

Below that line, a tide chart draws the water level across your sail window as the curve it really is — the water moves fastest around mid-tide and eases off toward the turn, so the line bows rather than running straight. Any high or low falling inside your window gets a dot and a label right on the curve (▼ 3:24p), and the hours of your sail are ticked along the bottom in your club's timezone; a sail shorter than an hour is labeled with its start and end times instead. A short window around slack water stays deliberately flat — a near-motionless hour should read as calm water, not a dramatic swing.

On a wider screen, the Today card on your club home carries the same pair — the tide line with its station credit, and the curve beneath it — for the next eight hours rather than a sail window, so you can read the water before you open anything.

A few things to know:

• Where a tide station is close enough to describe your water, times come from official NOAA tide predictions — US waters, with a station within about 30 km of your club's home location. Heights match the published tide tables, including negative low waters. The station name is shown at the end of the tide line, so you can see where the numbers come from at a glance: ▲ High 6:14 pm (8.2 ft) · ▼ Low 12:50 am (0 ft) · The Battery. Hover the line for the full station credit ("NOAA tide predictions — NEW YORK (The Battery)").
• Everywhere else, Zeil falls back to modeled sea level data, which is not an official tide table: near a turn of the tide it can run an hour or more out of phase with the real water. These lines carry no station name — a tide line without one is modeled, and hovering says so. Check official tables where precision matters.
• On non-tidal waters (lakes, for example), no tide information is shown at all — that's expected, not an error.
• Modeled tide data reaches only about a week ahead, a shorter horizon than the wind forecast. Station predictions have no such limit, so clubs near a NOAA station see tide times on sails further out too.

The Sail Brief

The Sail Brief is a short, plain-English advisory generated for a sail, typically a day or two before. It pulls together:

• the forecast for your window,
• the tide schedule for tidal waters (state at the start of your sail and the highs and lows around it, named to the tide station where there is one),
• the boat's characteristics,
• the crew and skipper on board, and
• your club's local knowledge notes (hazards, tides, local quirks the club has recorded).

From that it writes a few sentences: a read on the conditions, a suggested sail plan, safety considerations, a note for the skipper, and useful details like the sunset time.

There are two flavors — a lighter brief for crew and a more detailed one geared toward the skipper.

Requesting a fresh brief

The brief generates automatically as your sail approaches, and regenerates if the forecast shifts meaningfully. You can also request a manual refresh from the reservation; this is rate-limited, so it may not refresh instantly every time.

Reminders and weather alerts by email

Two emails bring the conditions to your inbox, both controlled in your notification preferences:

• Sail reminder — the day before a sail you're on, Zeil emails you a reminder with an excerpt of the Sail Brief (the Sail brief category).
• Weather alert — if you're the skipper and the forecast turns significantly rougher after a brief has already gone out (sustained wind of 20 knots or more, or gusts of 25 knots or more), Zeil emails you an alert (the Weather alerts category).