I have kayaked in ponds, lakes, marshes, on the Hudson River (upstream is a bitch), in the Caribbean, and out in big salt water over the years. Except on quiet ponds, it's a good workout to go a few miles, especially in wavy gravy and wind. I have never done white water but yesterday we had to deal with lots of wake from cigarette boats, ferries, etc. Fun.
Kayaks have almost entirely replaced canoes for water recreation. Even Old Town Canoe makes kayaks. It's a good thing for older folks with bad knees or lower back issues because it's all upper body - torso, shoulders, arms.
I realized yesterday when Mrs. BD and I did a couple of miles in a good sea chop that I never even watched an instructional video. Thus, a kayak post. I realize that I have been trying to strong-arm the craft instead of using my entire body to move it. Also, I was not making "the box."
My Mom loved to kayak the upper Connecticut River, the Housatonic, and the Cape Cod lakes and marshes in her 80s. A pip, as I have said before. Like me, she did not know the word "relax." The old-time Yankees never sat down except for a cocktail, and the old gal weighed the same at 80 as at 25. Energetic and a small appetite, like her kids.
Proper Technique for Paddling a Kayak
How to Sit
Kayaking-Basic Paddling Techniques
Kayaking For Fitness
3 Golden Rules of Recreational Kayaking
How to Kayak : How to Not Capsize your Kayak
How to Roll a Kayak
Sea Kayak Self Rescue - The Ladder
This is fun: My First Big Shark from the Kayak
More fun: What not to do when you fall out of a kayak
Search Youtube - there are tons of videos