Shorter Oars vs Longer Oars?

[Charlie43]

The following is a snippet from an article on the physics of rowing.

The researchers found that longer oars more efficiently transfer energy from the rower to the boat, which is good for endurance races. But shorter oars are preferable for sprints, where rowers aim to zip through the water as fast as possible. “Endurance [racing] is about being able to row for long periods of time with maximum efficiency,” Benzaquen says, so a long oar is the ideal choice. In sprint races, however, speed trumps an athlete’s energy consumption. “If you spend all your energy in 10 seconds that is not a problem because the race is over quickly.” Shorter oars allow rowers to paddle faster. And even though rowers waste more energy moving the oar in and out of the water, the team’s calculations show that the increased stroke rate more than compensates for the loss. https://physics.aps.org/articles/v12/63

What is the impact of those findings for untrained, unconditioned, recreational rowers who won't be racing?  Opt for oars long enough to be reasonably efficient, but short enough to be easy to get out of the way. E.g., if the boat being rowed is a tender meant to get passengers to and from a mother ship to a nearby landing point, then nearly any sticks will work well enough, and it's better if they are easy to stow, plus look pretty (because people will be watching and judging). OTOH, if the boat being rowed is meant primarily to be a casting platform, the fish don't care what the oars look like, nor should you. What matters is ease of effort as one positions the boat for the next cast and that the oars can easily be put out of the way on each cast.

But as the distances to be covered increase, it makes sense to select a length that maximize efficiency, and here we come to "one's preferred stoke rate". If your preferred cadence on a bike is high, you're likely to prefer a high oar-stroke rate in a boat. Trying to do that with long oars, and especially those with big blades, will fatigue you quickly. If you prefer a leisurely oar-stroke rate, say 20 or less per minute, then you can swing a longer oar comfortably and sustainably *provided*, again, that you haven't over-sized your blade. So, it isn't just oar length that matters, but blade size, oar balance, intended stroke rate, intended duration, plus the prevailing sea-conditions, where the usual advice is "Rough water; narrow blade."