David asked:

I am in the market shopping for a canoe. I don't know if I should buy a
aluminum one or a royalex one.

Aluminum:
Advantages: can usually find a used one fairly cheaply
Keel makes them track fairly straight
Are practically indestructible

Disadvantages:
Heavy
Keel makes them somewhat harder to turn
Keel can get hung up on rocks in a shallow river
Noisy
Aluminum transfers cold from water
Did I mention heavy?

ABS
Advantages:
Somewhat lighter
Quieter
Fairly rugged
Maneuvers more easily
Surface is easier to kneel on

Disadvantages
More expensive
Doesn't wear as well as aluminum
More difficult to keep on a straight line
Hull subject to dings from rocks (although MUCH more sturdy than fiberglass)

I personally prefer ABS but If I were in the market for an aluminum boat , I
would look for a used Grummen (sp). They are fairly common and are pretty
bulletproof.

HTH

Mike