Boats suitable for racing. Depending on how fit you are there are racing classes for almost all types of boats. These designs are fast for the class of boat they fit into.
How fast is your boat? Do you know? Does the question even make sense? Isn't any boat going to go faster if you apply more power to making it move? What people really should ask is" "how efficient is your boat?"
There are a lot of different kinds of racing kayaks, but almost all have the characteristic of being fast.