Logbook Tab — automatic & official log
Record your navigation live (position, weather, speed), replay your crossings in immersive mode, get AI copilot advice, calibrate your polars from real passages, and keep a printable official maritime-format logbook.
Where to find it
Sidebar › Log (bookmark icon).
The tab opens on the Auto sub-tab. A second Official button switches to the regulatory logbook.
Hierarchy
Log (sidebar tab)
├── Auto
│ ├── Recording interval (5 min / 15 min / 30 min / 1h)
│ ├── Start / Stop recording
│ ├── Export CSV / GPX
│ ├── Clear logbook
│ ├── Navigation Copilot (visible during recording)
│ ├── Entries list (position, speed, wind, pressure, ship detections)
│ ├── AI Polars (learned from crossings)
│ ├── Crossing History (summaries + replay)
│ ├── Crossing Summary (modal on stop: stats, AI narrative, learning, replay)
│ └── Crossing Replay (immersive panel: playback, speeds, layers, route comparison)
└── Official
├── Vessel info (name, registration, flag, crew…)
├── New voyage (departure port + date)
├── Sessions (collapsible, one per voyage)
│ ├── Add entry (detailed maritime form)
│ ├── Entries table
│ ├── Close voyage (arrival port + date)
│ ├── Print / PDF
│ └── Delete voyage
Auto sub-tab
Live recording (Start / Stop)
What it's for: automatically log your navigation at a fixed interval. At each step the app captures your position, heading, speed over ground, and — when available — wind and pressure. Position comes first from your Signal K instruments, otherwise from the browser/device geolocation.
How to use it: 1. Pick the recording interval in the dropdown (clock icon): 5 min, 15 min, 30 min or 1h. 2. Click Start (green button). 3. Allow geolocation if the device prompts you. 4. A blinking red REC indicator appears at the top: recording is running. 5. To stop, click Stop (red button). 6. If the session has at least 2 entries, the Crossing Summary modal opens automatically.
Options & settings:
| Control | Role |
|---|---|
| Interval dropdown | Sampling cadence: 5 min, 15 min, 30 min, 1h (editable only when stopped) |
| Start | Begins the recording session |
| Stop | Ends the session and offers the summary |
| REC indicator | Blinking red dot = recording active |
| CSV | Exports all entries to a CSV file |
| GPX | Exports the track to a GPX file (openable in other software) |
| Trash icon | Clears the entire auto logbook |
Tips & limits: - The interval can only be set before starting; stop then restart to change it. - Without connected Signal K instruments, wind and pressure may stay empty; position then relies on device geolocation. - The export buttons and trash icon only appear once the logbook holds at least one entry. - Clearing the logbook also removes the track available for replaying unsaved crossings.
Entries list
What it's for: review each recorded sample, newest first.
How to use it: 1. Scroll the list below the controls. 2. Click an entry to center the map on its position.
Options & settings: - Each row shows: date/time, speed over ground (kts), heading (°), position (lat/lng), wind (kts) and pressure (hPa) when available. - Ship detection entries are highlighted (amber left border, ship icon) and flag a vessel spotted without AIS ("dark vessel") with bearing and distance.
Tips & limits: - Missing values (wind, pressure) mean no data was available at that moment.
Navigation Copilot
What it's for: an AI assistant that analyzes your conditions underway and delivers advice (info, caution, warning). It only appears while recording.
How to use it: 1. Start a recording: the copilot card appears below the controls. 2. Let it analyze automatically, or click Analyze to force an immediate analysis. 3. Read the latest advice; expand the history to revisit earlier tips.
Options & settings: - Analyze: triggers an on-demand analysis (disabled while there are no entries). - Color dot: advice severity (green = info, amber = caution, red = warning). - MCP badge: indicates the copilot is querying your connected instruments. - History button: expand/collapse previous advice.
Tips & limits: - The copilot needs access to the AI server; offline, it may stay in a waiting state. - It draws on the active polar, the destination waypoint and instrument data when available.
AI Polars
What it's for: automatically calibrate your boat's performance profile from your real crossings, rather than the theoretical polar alone.
How to use it: 1. Sail with a polar selected and record your crossings. 2. When you save a crossing summary, the AI polar automatically absorbs the passage data. 3. Review the performance grid and indicators at the bottom of the logbook list.
Options & settings:
| Element | Role |
|---|---|
| Crossings | Number of crossings used |
| Coverage | Share of the TWA/TWS grid populated |
| Confidence | Overall reliability of learned data |
| Avg. efficiency | Real vs theoretical performance |
| Performance grid | Mini heatmap of speeds by wind angle/strength |
| 5D Wave Derating | Collapsible section: speed loss by wave height, period and direction |
| Period selector | Chooses the wave period shown in the 5D grid |
| Trash icon | Resets the learned polars |
Tips & limits: - With no learned data, a message invites you to complete crossings with a polar selected. - Learning is more reliable when a varied range of wind angles/strengths is covered.
Crossing History
What it's for: find your saved crossing summaries, with their statistics and narrative, and relaunch a replay.
How to use it: 1. Scroll down to Crossing History. 2. Click a row to expand/collapse its narrative. 3. Click the play icon (▶) to replay the crossing. 4. Click the trash icon to delete a summary.
Options & settings: - Each row shows date, distance (nm) and duration (h). - Play icon: opens the immersive replay (see below). - Narrative: generated story, with key terms highlighted.
Tips & limits: - Replaying from history requires at least 2 samples to remain for the session; if the logbook was cleared, the replay will report that no data is available.
Crossing Summary (on stop)
What it's for: an automatic recap shown when you stop a recording with at least 2 entries.
How to use it: 1. Stop the recording: the modal opens. 2. Read the statistics (distance, duration, avg/max speed, avg/max wind, polar efficiency). 3. Let the AI narrative generate (an offline narrative appears if the server is unavailable). 4. Click Replay to launch the replay, Save to archive the summary, or Close.
Options & settings: - Save: archives the summary in the history; if a polar is active, the crossing also automatically feeds the AI polars (a "Polars updated" indicator appears). - Replay: opens the immersive replay panel and closes the modal. - Close: closes without archiving.
Tips & limits: - The summary does not appear for sessions with fewer than 2 samples. - The Save button is inactive while the narrative is still generating.
Crossing Replay (immersive panel)
What it's for: replay a crossing like a movie, scrubbing the track through time with live statistics, weather layers and comparison to the planned route.
How to use it: 1. Launch the replay from the Crossing Summary (Replay button) or from the History (play icon). The Log tab then shows the replay panel at the top. 2. Click Play (▶) to roll the crossing forward; Pause to freeze. 3. Set the playback speed (1x to 32x). 4. Drag the scrubber to position yourself at a precise moment. 5. Click the cross to close the replay.
Options & settings:
| Control | Role |
|---|---|
| Play / Pause | Starts or freezes playback |
| Speeds 1x → 32x | Accelerates playback |
| Scrubber | Manual positioning in time |
| Time indicator | Elapsed / remaining time |
| Stat chips | SOG, VMG, wind, heading, avg/max speed, pressure, waves, position |
| Distance & XTE | Traveled/total distance and cross-track error (port/starboard) |
| Route comparison | Actual vs planned distance and delta (if a route matches) |
| Color by | Wind / Speed / Pressure — changes the track coloring |
| Planned route layer | Shows the planned route (if matched) |
| Wind arrows layer | Shows wind arrows along the track |
| Weather field layer | Shows the weather field |
| XTE corridor layer | Shows the cross-track corridor (if matched) |
| Follow boat | The map continuously recenters on the replayed position |
Tips & limits: - The Planned route, XTE corridor layers and the route comparison are only available if the app finds a planned route matching the crossing. - If the logbook was cleared after saving, the panel reports that replay data is no longer available.
Forecast vs logged wind
What it's for: compare the wind actually recorded in the ship's log against the wind the loaded GRIB predicted, at the same places and times. It surfaces the forecast's bias — a sanity check before trusting it for routing.
How to use it: 1. Load a GRIB file and have log entries carrying a recorded wind within the GRIB's time window. 2. The Forecast vs logged wind card appears in the Auto sub-tab (collapsed by default; hidden if there are no matching points). 3. The header shows an at-a-glance speed bias in knots (e.g. "+1.4 kn"), colour-coded green / amber / red by agreement. 4. Expand it to see the detail over the N matching points.
Options & settings:
| Tile | Meaning |
|---|---|
| Speed bias | Mean signed error (kn). Positive = the GRIB over-predicts wind. |
| Speed RMSE | Typical scatter of the speed error (kn). |
| Dir bias | Mean signed direction error (°) — only if the log has wind direction. |
| Dir RMSE | Direction error scatter (°). |
Tips & limits: a plain-language line concludes, e.g. "The GRIB reads ~{v} kn high on average here — expect slightly less wind than forecast" (or the opposite if it under-predicts). Direction tiles appear only when the log records wind direction. The card is hidden with no GRIB loaded or no log point inside the GRIB's time coverage.
Official sub-tab
Regulatory logbook in maritime format (CERFA style): vessel info, dated voyages, detailed hourly entries, PDF printing.
Vessel info
What it's for: fill in the boat and crew identity once, carried over to every new voyage and to printing.
How to use it: 1. Click the ship icon in the official log header. 2. Fill in the fields. 3. Click Save (or Cancel).
Options & settings:
| Field | Content |
|---|---|
| Vessel name | e.g. S/Y Odyssey |
| Registration | e.g. AC 123456 |
| Flag | e.g. FR |
| Hull type | Mono / Cata |
| Length | in meters |
| Home port | e.g. La Rochelle |
| Skipper | skipper's name |
| Crew | names separated by commas |
Tips & limits: - Once saved, the vessel info shows as a summary under the header (name — registration — skipper + crew count).
New voyage (session)
What it's for: create a log session for a given passage, to which you attach the hourly entries.
How to use it: 1. Click New voyage (green button, header). 2. Enter the Departure port and Departure date. 3. Click Create (or Cancel).
Options & settings: - Departure port: required text field (without it, creation is blocked). - Departure date: date picker (defaults to today).
Tips & limits: - Each voyage appears as a collapsible session in the list, identified by "Departure port → Arrival port" and dates.
Voyage entries
What it's for: manually log a complete maritime entry at a given moment (position, navigation, weather, sail plan, watch, event…).
How to use it: 1. Expand a session (chevron). 2. Click Add entry. 3. Fill the form (fields prefill from the previous entry as a base). 4. Click Add to confirm (or Cancel). 5. Delete a row via the trash icon in the table.
Options & settings: the form covers:
| Section | Fields |
|---|---|
| Date/Time & Position | Date/Time, Latitude, Longitude |
| Navigation | True heading, Compass heading, SOG, STW |
| Weather | Wind (kts), Wind dir., Beaufort (auto-computed), Pressure, Sea state (0–9), Visibility (good/moderate/poor/fog), Temperature |
| Sail plan / Engine | Sail plan (motor, full sail, 1–3 reefs, storm jib, bare poles, motorsail, spinnaker, gennaker, other), Engine hours, Fuel level (%) |
| Watch & Event | Watch (A/B/C/D), Watch leader, Event (departure, arrival, watch change, sail change, weather change, MOB, equipment failure, sighting, anchoring, fueling, customs, incident, observation) |
| Depth & Log | Depth (m), Log (NM) |
| Notes | Free observations, maneuvers, events |
Tips & limits: - Beaufort is computed automatically from the entered wind speed (read-only field). - The table summarizes: date/time, position (DMS), heading, SOG, wind (kts + dir + Force), sea state, barometer, sail plan and notes.
Close voyage
What it's for: record the arrival port and date to officially close the passage.
How to use it: 1. On an open session (no arrival port), click the anchor icon. 2. Enter the Arrival port and date. 3. Click OK (or cancel via the trash icon).
Options & settings: - The arrival port completes the session title ("Departure → Arrival").
Tips & limits: - The anchor icon only shows while the voyage has no arrival port.
Print / PDF & Delete
What it's for: produce a printable/PDF version of a voyage's official log, or delete a session.
How to use it: 1. On a session header, click the printer icon to generate the print view (then print or save as PDF via the browser/system). 2. Click the trash icon to permanently delete the voyage.
Options & settings: - Printer icon: print / PDF of the session. - Trash icon: delete the voyage.
Tips & limits: - Deletion is permanent and removes all entries of the session.