At our ages, soon we’ll be learning new things every day, that we learned the day before.
I probably am getting a little sloppy at max effort. I have a 2008 Current Designs 'Storm GT 17 foot, and a 2008 Current Designs Whistler 14.5 foot. I did my fastest speed runs at Morrison Rockwood State Park, near Morrison Illinois. The Lake is man made and just over three quarter of a mile long. I run out of lake about the same time I run out of steam. There is no detectable current, and tests were on windless days. My best speeds (Garman GPS) for more than one minute were 6.2 with the Whistler - no load, 6.2 no load with the Storm, and 6.4 loaded. I did not expect the Whistler to be that fast. My best five minute times were 6.0 and 6.1, I have never made six minutes over 6 mph in either boat. I used an Aqua Bound Manta Ray Hybrid paddle for the speed runs. I am not skilled enough to sustain more than 4.9 mph with my Greenland paddle.
Magooch, at maximum effort, lowering the angle, for me, causes a bit of wavering in direction that costs a bit of speed. I do go faster with the rudders up than down. I probable should use the spray skirt more often.
At our ages? A member of one of the clubs I am in, died in 2017. I last paddled with him in 2016, he was 91 years old. His name, Murray Peskin, he was a scientist on the Manhattan Project in WWII, and a wonderful gentleman.
I once had a pair of gentlemen come up to me at a takeout and ask me what my boat weighed. They were in their 80s and told me that they were considering something lighter than their 85 pound wood/ canvas tandem.