Telltale

sailing · sailing knowledge

Record a sail and review it: replay, polar and the fleet

Record from a phone, a laptop or a boat computer. Afterwards the session page replays the sail on the chart, compares every stretch with your polar and, in a race, sets your times against each rival.

By Telltale Team · Reviewed

Set it up

Step-by-step setup in Help
  1. Choose how to record: the phone app, Telltale Desktop on a laptop aboard, or a boat computer. Ways to record
  2. Connect the instruments if the boat has them. Without them you still get the GPS track. Connect instruments
  3. Add the boat’s polar, so every stretch can be compared with it.
  4. Record before you leave the dock. Afterwards the sail is under Sessions. Sessions

Ways to record

Any phone gives you the track. Instruments tell you why.

The phone app records its own GPS on any boat, and the boat’s instruments when it is on the boat Wi-Fi with a Telltale recorder aboard. Telltale Desktop on a laptop, or a small boat computer on the boat network, records every instrument whenever they are on, without anyone pressing a button.

Boat speed through the water and true wind are what make the review useful: with them, every stretch can be compared with your polar. With GPS alone you get the track, speed over ground and the tacks.

The Telltale Record page: three ways to record, your phone, a laptop aboard and a boat computer, with the apps for each.
In TelltaleRecord from a phone, a laptop or a boat computer. The phone records GPS on any boat and the instruments on the boat Wi-Fi. Telltale Desktop on a laptop, or a small boat computer, records every instrument whenever they are on. Choose how to record

References 1

The session page

The track on the chart, the numbers beside it and the lanes under it, all on one clock.

Each sail becomes a session. The track is coloured by tack, with motoring in blue. The panel on the right sums the sail up, and the lanes along the bottom run wind angle, boat speed and true wind against time. Move the cursor anywhere and the boat, the lanes and the readings move together.

A Telltale session for 2 September 2026: the track on the chart coloured by tack, the summary beside it, and lanes for wind angle, boat speed and true wind below.
Nightjar’s copy of Off Piste’s 2 Sep evening race, as her owner sees it.
The Summary panel: 10.0 NM, 1h 52m under way, 10.2 kn top speed, 5.3 kn average, 27.2 kn top true wind and 5 tacks; time sailing and motoring; and what stood out.
The Summary: distance and speeds, time sailing and motoring, and what stood out.

Replay and the lanes

Press play, or drag along the lanes to any moment.

Play the sail back faster than real time, or drag the cursor to a moment. + Lane adds any recorded channel: speed through the water, percent of polar and its target, speed over ground, true wind direction, depth, heel, apparent wind, sea temperature, pressure and the crew’s heart rate. Colour by switches the track from tack to percent of polar, and Analyse opens the chart and lanes full screen.

The lanes under a session: the board bar, boat speed, percent of polar, wind angle and true wind, with three numbered stretches marked.
Boat speed, percent of polar, wind angle and true wind. The numbered stretches are where the most time went.

How close you sailed to your polar

Every stretch against the boat’s own polar, summed up in one sentence.

The Performance tab compares boat speed with the polar’s target for the true wind and angle at each moment. It opens with the answer, then breaks the sail down into upwind, reaching and downwind, with the minutes lost on each. Where the time went lists the worst stretches; each is numbered on the lanes and the chart, so you can go straight to it.

Race only or Whole sail sets what counts, and the owner can set the gun and the finish if the recording ran long. It needs boat speed, wind and a polar. A log that reads low makes every stretch look slow, so calibrate it first.

The Performance tab of a Telltale session: the track coloured by percent of polar with three numbered stretches, and the summary of where the time went.
The track coloured by percent of polar: red below 80 %, through blue, to green at 100 % and over.
Upwind she sailed closest to her polar at 87 %; downwind and reaching cost about 15 minutes. By kind of sailing: upwind 87 %, reaching 80 %, downwind 81 %, with minutes lost. Where the time went: three stretches with their times and percentages.
The answer first, then each kind of sailing and the three stretches that cost the most.

Against your rivals

In a race, each boat heard on AIS is set against you, mark by mark.

The Fleet tab lists the boats in your division with each one’s time behind or ahead of you at the start and at every mark, and what it gained or lost on the leg into it. The finish order follows, with elapsed times. Race and Nearby widen the list to the whole race, or to every boat sailing near you.

Their tracks are drawn on the chart with yours, so the replay shows who went which way and when it paid. The fleet comes from AIS, so a boat without it isn’t there.

The Fleet tab of Off Piste’s Fraser River Lightship Race: each rival’s time behind her at the start and the finish, with minutes lost, then the finish order with elapsed times.
Off Piste in the Fraser River Lightship Race, 3 Oct 2026, against her division.
The Fraser River Lightship Race 2026 replay at the starting gun: Off Piste among the fleet heard on AIS, with speed, boat speed and true wind plotted below.
In TelltaleReplay the whole fleet. A race’s own page replays every boat together from the starting gun, with each boat’s speed and the wind in the lanes under the chart. Open the Lightship replay

Which forecast was right

Each model’s wind along your track, against what you measured.

The Forecast tab samples every model along the track at the time you were there and says in one line which came closest and by how much. Under the chart of measured wind, the models are listed closest first; tap one to draw it in ink. The current, leg by leg, is one bar per leg: green where the tide carried you, red where it held you back, with the net over the sail above it. Tap a leg to replay it.

The Forecast tab: HRDPS was closest, off by 4.0 kn on average; the measured wind charted against each model, listed closest first; and the current leg by leg as green and red bars, a net 1.3 km against her.
The Lightship race again: the closest model, the wind along the track, and the current leg by leg.

How Telltale corrects forecasts

Notes, sharing and export

Keep the debrief with the sail, and take the data anywhere.

Under More, the crew add notes pinned to a moment of the sail, and the owner chooses who can see it: only the crew, crew and followers, or anyone with the link. Make a video turns the replay into a clip. GPX, CSV and FIT downloads and an Expedition export take the data to other tools, and the people aboard can send the sail to Strava.

The More tab: who can see the session, a debrief note field, comments, and Sharing and export with Make a video, GPX, CSV, FIT and Expedition export.
Who can see it, the debrief, and the exports.

Getting a recording worth reviewing

A few minutes at the dock saves an empty debrief.

Most gaps in a review start before the boat leaves.

  • Start recording before you leave, so the start of the race isn’t lost.
  • Check the instruments read sensibly: boat speed close to SOG in still water, the wind angle swinging when you tack.
  • If the phone is the recorder, keep it on the boat Wi-Fi and charged.
  • If an instrument drops out, its lane shows the gap rather than a guess.
Sources and review

Official references checked on 2026-10-11. Product details and schedules change; the provider’s page is the current word.

Take it to the water

Check the stations before you leave, then record the sail for the debrief.

Open ConditionsRecord a sail