The Coaching Intelligence Layer
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.
The Physics
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.
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.
Heave-axis oscillation through the drive — a proxy for blade depth control and body stability that GPS speed alone can't see.
Turbulence signature at extraction — a rushed or dirty finish shows up here before it shows up in your split.
On The Water
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. The player above is that same trace, replayed from a real outing rather than staged.
SPM, split, heart rate and drive quality, updated every stroke.
Surge waveform, 4-second rolling window — the catch and check signature as it happens on the water.
After The Row
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 of SPM, velocity, HR, check, bounce and wash on one timeline.
Lifetime & PBs — 500m pace, 1km, 2km and peak speed, tracked automatically across every session.
Built For The Boat
No extra hardware — the phone in your bow-mount is the sensor. Optional Wear OS watch adds wrist-impact catch timing.
Polar H10 or any standard BLE heart-rate strap — Garmin included — streamed live alongside torso pitch and roll for lunge and posture detection.
Same metric language on the water and on the erg, so a winter of erg bests compares directly to spring speed.
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