The Coaching Intelligence Layer

Your stroke, coached.

Bowball doesn't just log your row. It runs the same physics analysis a coach on the bank would — catch, drive, check, bounce, wash — and turns it into technique feedback you can actually act on, stroke by stroke and session over session.

Request Early Access See it live →
Surge waveform — how Bowball sees a stroke · illustrative
24
SPM
119
Heart rate
−2.10
Check factor
The Physics

Every stroke has a shape. Bowball reads it.

A 200Hz IMU stream, resolved into boat-frame surge, sway and heave, feeds a phase detector that finds catch, drive, and finish automatically — then scores what happened in between.

Check

Deceleration at the catch

How hard the boat is checked before the blade locks on — a clean catch keeps the hull running; a late one bleeds speed you already paid for.

Bounce

Vertical disturbance

Heave-axis oscillation through the drive — a proxy for blade depth control and body stability that GPS speed alone can't see.

Wash

Finish quality

Turbulence signature at extraction — a rushed or dirty finish shows up here before it shows up in your split.

On The Water

Live feedback, glanceable at full slide.

The HUD surfaces SPM, split, heart rate and drive quality at a glance; the live trace shows the actual surge waveform as it happens — the same catch spikes and check troughs your coach would flag from the bank.

Bowball live HUD screen showing stroke rate, heart rate, check factor and drive time mid-session
HUDreal-time stroke metrics
Bowball live acceleration trace showing the boat surge waveform through several stroke cycles
Live Tracesurge waveform, 4-second window
After The Row

Every session, kept — and worth revisiting.

GPS track, split, heart rate and the full metric trace are synced and scrubbable after every outing. Career Stats rolls it all up: lifetime distance, stroke count, personal bests by 500m, 1km and 2km.

  • GPS-mapped replay — colour-coded by speed, scrub to any point in the row.
  • Multi-trace overlay — SPM, velocity, HR, check, bounce and wash on one timeline.
  • Lifetime bests — 500m pace, 1km, 2km and peak speed, tracked automatically.
Bowball session history screen showing a GPS-mapped 9.76km row with a multi-metric trace chart
History9.76 km session
Bowball career stats screen showing lifetime sessions, distance, strokes, time on water and personal bests
Career Statslifetime & PBs
Built For The Boat

One phone. Every sensor that matters.

On the water

Phone IMU + GPS

No extra hardware — the phone in your bow-mount is the sensor. Optional Wear OS watch adds wrist-impact catch timing.

Heart rate

Polar & Garmin compatible

Polar H10 or any standard BLE heart-rate strap — Garmin included — streamed live alongside torso pitch and roll for lunge and posture detection.

On the erg

Concept2 PM5

Same metric language on the water and on the erg, so a winter of erg bests compares directly to spring speed.

Private Beta

Bowball is rowing out in private beta.

Distribution is by invite while we finish the on-water validation pass. Get in touch and we'll add you to the next round.

admin@bowball.net