About Critical Mass Racing
Critical Mass Racing is an open-source sailing performance laboratory that turns instrument data into practical insight. It combines post-race analysis, AI-assisted coaching, reference material, and experimental tools to help sailors better understand how their boats perform.
The software may be used, modified, and distributed under the terms of the Apache License 2.0. See the LICENSE file in the GitHub repository for the complete licence terms.
Technical details are contained in the README.md and ARCHITECTURE.md files.
About Critical Mass
Critical Mass is a J/80 raced in one-design configuration. We are weeknight “beer can” racers who want to better understand where we make gains, where we lose time, and where the biggest performance gaps lie.
This project turns our onboard instrument data into practical post-race coaching. It is designed specifically for a J/80 and tailored to the instruments installed on Critical Mass. It is not intended to replace crew judgment, tactical discussion, or time on the water. Its purpose is to give those conversations a reliable baseline.
Onboard instruments
Our data-logging system includes:
- Speed and depth — B&G DST810
- Wind — B&G WS310
- GPS and compass — B&G ZG100
- Data recorder and gateway — Actisense W2K-1
- Additional race data — Velocitek ProStart and Vakaros instruments
The system records available instrument data throughout each race, creating a second-by-second account of the boat’s speed, heading, wind conditions, position, heel, and other measurements.
The goal
The goal is to establish a useful baseline for what went well and where we can improve at three levels:
- How well we executed our tacks, gybes, and roundings
- Whether we sailed to our target polars
- Whether we chose the right or wrong side of the course
Put together, these views turn each race into a data point instead of just a memory. With enough races, we can begin to distinguish between nights that were fast because of favourable conditions and nights that were fast because of better technique.
That distinction is what makes the information coachable — and gives us something specific to work on the next time we leave the dock.
Fitting It All into the J/80
All electronics are removed from Critical Mass at the end of each season, as we are constantly experimenting with new equipment.
We use custom 3D-printed mounts for the Vakaros instruments and Velocitek ProStart—thanks, Dwayne! These mounts are necessary because of the location of our Cunningham.
We have also developed several temporary companionway sliding-hatch mounting systems, allowing instruments to be added, removed, and repositioned easily.
The NMEA 2000 bus is zip-tied to the mast, keeping it accessible for maintenance and equipment changes.
The Actisense W2K-1 is mounted for quick removal. It comes home after every race, along with the Vakaros instruments and ProStart, because these devices contain our race data.