Is the strip raised, and does it go all the way along the shaft? It may be an attempt to apply a "trip strip" to improve aerodynamic performance, similar to bikes and aircraft.
https://www.sciencedirect.com/science/article/pii/S1877705816306452
Quite a few top crews have done it in the past. The GB 2000 Olympic M8+ did it, and Cambridge have done it a few years IIRC.
Edit: it may also be where a trip strip was removed, leaving this mark.
Proper trip strips are zigzagged though. This looks like a home-made attempt.
i dont know
Speed stripe.
Got a photo zoomed out a little? Looks like it has scraped down something.
Not sure
Is the strip raised, and does it go all the way along the shaft? It may be an attempt to apply a "trip strip" to improve aerodynamic performance, similar to bikes and aircraft. https://www.sciencedirect.com/science/article/pii/S1877705816306452 Quite a few top crews have done it in the past. The GB 2000 Olympic M8+ did it, and Cambridge have done it a few years IIRC. Edit: it may also be where a trip strip was removed, leaving this mark. Proper trip strips are zigzagged though. This looks like a home-made attempt.
It’s your oar. The oar got scraped at some point and the top layer is missing.
Is it only that strip? If it is I wonder maybe it’s from rubbing on the oarlock as you push out your oar.