Seeing Opportunities for Speed
The boat speed curve is a simple tool that opens the door for coaches to see the dimensions of time and distance and evaluate rowing technique based on boat acceleration.
Purcerverance Boat Speed Curves are developed from video taken of a crew from a stationary camera aimed perpendicular to the path of the boat. The boat is at a distance from the camera typically 5 to 10 times the length of the boat to minimize the parallax error during the analysis. The video captures the boat and crew for approximately two strokes. Once the video is captured the analysis is performed using video software that includes tools to designate a reference distance and track movement and time.
The video analysis process involves designating a reference (distance) dimension within the video which is typically on the length of the boat. Once the reference measurement is input each frame within the video has a designated (recording) time and a known distance. With the time and distance known, boat speed from frame to frame can be calculated. Additional data relating to rowing technique and the time the crew reaches designated positions of the stroke are identified manually.
The time, distance, speed and technique position data are uploaded to the Purcerverance spreadsheet. The spreadsheet uses the data to calculate movement, speed, acceleration and efficiency of the crew’s rowing technique. The spreadsheet also includes a rigging analysis section to determine Drive Time, Blade Slip, Stroke Position, Stroke Ratio and Rate. This tool provides quantifiable insight for the coach to identify opportunities to improve performance.
I will be presenting two sessions of Seeing Opportunities for Speed at the 2018 Joy of Sculling Conference as well as a session on Individual Rigging. For more information on Purcerverance Boat Speed, Rigging and Technique Analysis sheets visit the website at: https://purcerverance.ca