One cool fact is that rowing offers a bigger efficiency advantage over swimming than biking over running:
The efficiency advantage of biking versus running is around 2.66x, the hour record on bikes is currently 56 km (56km/hr), and the fastest marathon run is around 21km/hr.
On rowing vs swimming, the current freestyle 1500m record is 14:31 (6.2km/hr), whereas the best time for single scullers is 2km in 6:30 (18.5km/hr), for an advantage of around 3x.
* I tried to pick roughly similar distances to compare.
I tried to find similar distances to compare, but it might have been better like you suggested to compare around similar times. One other thing is that the conditions in an indoor velodrome are pretty ideal vs being in the water, although you also can get currents and wind (although records cannot be certified unless winds are below some threshold I believe)
There have been opportunities to try running at world-record pace on a giant treadmill, with a crowd to watch you land on your ass while you try and run at a sub-5:00/mile pace:
For reference, I believe the pace Kipchoge ran for his world record is about as fast as I ran when I set our high school's 2 mile/3200m record. It's a solid record that I still hold 45 years later, but Kipchoge did it for 24 more miles. Insane, indeed.
The efficiency advantage of biking versus running is around 2.66x, the hour record on bikes is currently 56 km (56km/hr), and the fastest marathon run is around 21km/hr.
On rowing vs swimming, the current freestyle 1500m record is 14:31 (6.2km/hr), whereas the best time for single scullers is 2km in 6:30 (18.5km/hr), for an advantage of around 3x.
* I tried to pick roughly similar distances to compare.