I don't know the boat, but unless you want speed keep the rocker as it is and add a skeg. This will preserve your maneuverability which is also a good thing.
JohnK

: I don't know that model, Is it skin on frame, strip, stitch and glue??

: Rocker can contribute to stability, handling, speed, trim etc. and effects
: more than just tracking so I would be reluctant to start tampering with a
: proven design. If it is not proven, I would look for something closer to
: your intended usage.

: On the other hand, once it is build you can duct tape a section of cord or
: rope on the aft keel line until it is behaving the way you want and then
: make a permanent wood keel and glass it on. For more extreme paddling
: conditions you could add an adjustable skeg.

: You have me curious now, do you have a photo or link to the design?

: Reg