jeadstx wrote:My original oars were 7' long. Too short, but I was still able to row the boat. My new oars are 8.5' long, work better. Since I store them in the cockpit along the base of the seats, I didn't want them any longer.
Having oars you can't stow is certainly not practical. The formula would seem to suggest in that case to move the oarlocks a bit inboard to make them conform to the standard ratio.
Getting curious and looking around the web for this a bit, I found one person mentioning that the formula gives you oars that are "too short, if you are strong or your boat is fast". The DS is too wide to be "fast"; so definitely not a cause to go for anything different than that 7/25 ratio for the inboard loom. (I doubt that anyone who keeps oars as "occasional" propulsion, and doesn't have a rowing machine in the basement, would be "strong" in rowing terms).
On another site, people reported the need to re-jigger their rowing setup to make it work for them. In particular, they were adjusting the height of the oarlocks.
The width between the coamings on a DS seems to match what I can find for specifications on rowing rigs elsewhere. I suspect that if you are taller you might want a bit wider base, because your stroke would be longer. Fascinating topic.
(Edit: the standard spread is usually described in the context where people row with sliding seats. Interesting question whether not having a sliding seat means that a narrower spread would be better).