ranger wrote:
These veteran times, I think, have been limited more by physical capacities than anything else--conditions, technique, etc.
For instance, as it turns out, old foggie lightweights don't do much better than 1:48/18:00 for 5K.
That means that, at the ideal limit of 12 seconds per 500m over erg times, the physical capacities of the 60s rowers are limited to 2:00 pace, and with the difficulties that you note (bridges, traffic, steering, etc.), 2:05, 17 seconds over erg times seems to able a limit for negotiating the course, given physical capacities.
But what if a 60s lightweight, with good OTW technical skills, could do 1:39 for 5K OTErg.
Then, given a limit of 17 seconds per 500m over erg times, that rower might be able to do 1:56 for the Head of the Charles.
Rowing isn't all technique.
ranger
Here's an interesting story. Recently I won a 1000m race on a bent course on a river with high water by smart steering through turns and areas with fast current. I won with a 12sec margin. The guy who came in 2nd lost a lot of time. He didn't look over his shoulder and followed the bank closest to him. Almost entered a dead arm of the river. Sounds familiar?
This guy is 20 cm taller than I, 15kg heaver, 6 years younger and does 3 times the training hours. He is an OTW rower who has always raced in 4+, 8+ coxed boats. He is about 40 seconds faster than I on the 2k test on the erg.
On the afternoon of the same day, he participated in the open men's category. He had learned to look over his shoulder and finished in second in the final.
Still, I beat him in that particular race. On straight courses, I can beat him now and then. If there is wind and waves, that is.
Moral of the story: Steering is important, and it takes about one "accident" to learn that lesson. Good luck at your next race!