Pretty much everything I know about single-blade paddles.

WW
- short & wide is best/mandatory, also for shallow water.  More wet surface to power with.
- at least one spare is required, eventually a rock will take the paddle in your hands.
- bent-shaft is a bad idea, you need 2 power faces without confusion.
- Is a T-grip preferable?

Deep Water
- long & narrow is more efficient & easier to use.
- bent-shaft is most efficient, be aware if you like to use finess strokes.  Double-bents are neat looking, never used one, I suspect even more efficient & more limiting.
- variety of grips are available, but unidirectional grips are limiting.  Guide grips are sweet!


Hit up the paddle fetish folks on Solotripping.  Prepare for information overload.

id recommend getting ones with the copolymar plastic rock guard edges. it saves your wood a ton of damage if you decide to get wood paddles. for whitewater i would say go pure plastic, however.