About Cognoscere

Cognoscere is a sailing analytics web app for uploading, storing, and visualizing VKX race files from your Vakaros device. It is built for crews and coaches who need quick replay, race comparison, and cloud-backed file access, and to help you understand the numbers your Vakaros records so you can sail faster.

Return to Home Try Out Cognoscere

Quick Start

Open /cognoscere.
Sign in if you want cloud storage and sharing.
Upload a .vkx file by click or drag-and-drop.
Choose local-only or cloud+local processing when prompted.
Use play/pause, speed, and timeline controls to replay.
Switch between Track, Trail, and Heat map modes.
Load historical files from Select from Cloud or View Recent File.

Terminology: What the numbers mean

Your Vakaros records several values many times per second. Here is what the common abbreviations mean and why each one matters on the water.

COG (Course Over Ground)

The actual direction the boat is travelling relative to the ground, in degrees. Because of current and leeway, COG can differ from where the bow is pointing (HDG). It is derived from GPS movement.

HDG (Heading)

The direction the bow is physically pointing, from the compass/IMU. Comparing HDG to COG shows your leeway, how much the boat is slipping sideways versus tracking true.

SOG (Speed Over Ground)

Your true speed across the ground from GPS, in knots. Unlike boat speed through the water, SOG already includes the push or drag of current.

VMG (Velocity Made Good)

How fast you are progressing directly toward (or from) the wind or mark. High boatspeed at the wrong angle can still mean poor VMG, and VMG is the number that wins upwind and downwind legs.

Tips & Tricks for the Most Accurate Data

Cognoscere can only be as accurate as the data your Vakaros logs. A few habits make a big difference to how clean your replays and analytics look.

Mount it flat and secure. A device that wobbles or sits at an angle feeds noisy heading and heel data. Fix it firmly and as level as your mount allows.
Give it a clear sky view. Keep the device clear of the boom, sail, and metal fittings so the GPS antenna gets a strong fix.
Let it settle before the start. Power on a few minutes early so GPS and heading fully lock in before you record.
Charge fully. Low battery can throttle logging, so start each day topped up.
Bump the log rate to 10 Hz for smooth tracks and precise maneuver timing (see below).
Calibrate the compass at the start of a season or after remounting (see below).
Set your tacking angles so wind and lay-line calculations match your boat (see below).

Updating the Log Rate to 10 Hz

By default many devices log at a lower rate to save battery. Raising the sample rate to 10 Hz (10 readings per second) gives noticeably smoother tracks and lets Cognoscere pinpoint the exact moment of each tack, gybe, and speed change.

Open the Vakaros app and connect to your device over Bluetooth.
Go into the device / logging settings.
Find the log rate (sample rate) option and set it to 10 Hz.
Save/sync the setting back to the device before heading out.

Trade-off: higher rates use more battery and produce larger files, so start the day fully charged. For most racing this is well worth it.

Calibrating Your Vakaros

The compass/heading sensor drifts over time and reacts to nearby metal, so periodic calibration keeps HDG, wind, and lay-line numbers honest.

When: at the start of a season, after remounting the device, or if heading looks consistently off.
Compass calibration:follow the Vakaros app's guided routine, typically slow, smooth turns through a full circle away from docks and large metal structures.
Line marks:ping your start-line ends accurately on the water so Cognoscere's start-line and lay-line overlays line up with reality.
Confirm afterwards: sail a known straight line and check that HDG and COG agree in flat water with no current.

Using the Tacking Angle Buttons for Better Readings

Wind direction and lay-lines are calculated from your tacking angles, the angle your boat sails to the wind on each tack. Telling the device your real angles makes these calculations far more accurate.

Set them live: while sailing upwind on a settled course, use the tacking-angle button to capture your current angle for that tack, then do the same on the opposite tack.
Update as conditions change: your angles shift with wind strength and sea state, so re-capture in lighter or heavier breeze rather than trusting one fixed number.
Why it matters: accurate tacking angles sharpen the computed True Wind Direction, which in turn improves lay-lines, favoured-end calls, and the ladder-rung references you see in Cognoscere.
Do it early: lock in good angles during your pre-start tune-up so your first beat already has reliable references.

Customizing the UI

Both the Vakaros on-water display and Cognoscere's replay can be tailored to show what you care about most.

On the device

Choose which data fields appear on each screen (SOG, VMG, HDG, timer, etc.).
Rearrange pages so your key numbers are front and centre for your role.
Adjust brightness/contrast for glare and low light.

In Cognoscere

Switch Track / Trail / Heat visual modes to match what you're analysing.
Toggle individual boats on and off when comparing multiple files.
Flip between base map and satellite, and toggle lay-lines and ladder-rungs.
Control playback speed and scrub the timeline to any moment.

Map Capabilities

Track, Trail, and Heat visual modes

How to switch: use the map mode controls and choose Track, Trail, or Heat.

Track: draws the full race path for the selected race so you can inspect the complete route.

Trail: shows only recent motion (default ~50s) with fading opacity, making short-term maneuvers easier to see.

Heat: plots all points as density to reveal where boats spent the most time.

Playback controls and time navigation

Use Play/Pause to animate race progress and the speed control to accelerate or slow review.

Use the time slider to scrub to exact moments. Playback automatically stops at the end of the dataset.

Boat icons, stats, and tooltips

Boat icons rotate with heading and update as time changes.

Click a boat for detailed live stats, including timestamp, SOG, COG, and VMG/leg context when available.

Use per-boat toggles to hide/show individual files while comparing races.

Start-line, lay-lines, and ladder rungs

When line-mark data exists, Cognoscere renders the start-line plus calculated lay-lines.

Optional ladder-rungs can be toggled on to help assess angle and spacing references.

Weather and map style controls

Weather overlays are sourced from Open-Meteo (historical or forecast context by dataset time).

Use the style toggle to switch between base map and satellite view while preserving race overlays.

Cloud Workflow

Upload locally or choose to save to cloud when signed in.
Select files from Cloud Drive with previews and metadata.
Use sharing, export, rename, and map-loading tools from the file explorer.

Feedback & Suggestions

Cognoscere is built for sailors, and your input shapes it. Have a question, a bug to report, or an idea that would make it more useful? I'd genuinely love to hear it, please email me at liam@telltalesolutions.com.au.