The location of the Impeller affects the readings it gives due to the changing turbulence along the boat. If the boat is primarily used on straight courses we recommend that it is mounted near the cox, for convenience, and that it is then calibrated. If the boat is not just used on straight courses an Impeller Extension Lead should be used to position the Impeller approximately 5 metres from the bow.
The CoxOrb was invaluable in my boat race training and racing. The GPS system enabled me to track my lines and learn how to drive the fastest course possible on race day. Having everything I needed in one unit meant that no unnecessary weight was on board during racing and we could crank out the hull speed we desired.
Oxford Womens Boat Race Cox 2016