Cross-training: Swim, Cycle, Run & Kayak?

I went out a tandem Kayak with a more seasoned I kayaker (ok, that is not a real word) than myself. I was in the back so it was not to noticeable when I stopped paddling. I started out with a lot of energy and bad technique within the first mile I realized all my training did not apply here. With a few pointers I was able to make progress again and keep up with the pace.
We did have the occasional Otter siting and back-off when appropriate, although at one point we were surrounded, I believe the Otters get commission on every fine collected.
The details:

5.63 Miles
5.7mph Max Speed
3.1mph Avg. Speed
125bpm Max Heart Rate
88bpm Avg. Heart Rate