: Of course it's possible that the kayak you loaned had scratches in bottom or
: something which made it slower.

You hit on something there. Now, I am not too concerned about them out paddling me. When I got home my shoulders hurt so bad I just wanted to take some medicine and crawl up on the couch. Matter of fact I am still sore. I was seriously dragging on the last couple of miles. I had built two GP's the two night before and all the hand planing ...well I paid for it!

But the boat didn't impress me. It was scratched up some, not to bad though. It had a rudder and I was anxious to try a boat with a rudder (I know I don't want one now). It was a little windy at times and the boat wanted to weather cock. I found that extremely annoying, especially in such a light wind. So I had to keep the rudder down. I tried to lift it as much as possible and I was quite surprised and actually thought it was just my imagination, but I could feel a difference with the rudder up and down. I asked the owner if he had noticed it but he hadn't paddled it in a long time and said he rarely used the rudder anyway.

But what you saying makes sense. I can't believe a rudder makes much difference in drag but I could feel the difference. So obviously small amount are noticeable. Maybe there is not practical difference just day paddling but that not my reason for asking.