American Airlines provides a list of sports equipment they allow
without additional charges. Kayak paddles is not on the list.
Contacting AA, they indicated they set policies based on the needs of
the "Large group " of airline passangers. They will review their
policies when enough travelers request a change.

Why travel with a paddle? Kayak tour companies currently provide
boats, but expect one to bring their own paddles. If you ever consider
taking a toured trip which requires air travel please contact the
airlines now and request a policy change. AA may be contacted through
via http://www.aa.com/customerrelations/

Comments I made to AA we
At present kayak paddles are not on the allowable sports equipment
list (At American Airlines). In years past one could carry paddles
through in ski bags. With tighter security this is a less likely
option. Please add kayak paddles to the allowable sports gear list.
This list includes skies as one of the two checked baggage (at no
additional cost) list. Kayak paddles are similar in size, lighter in
weight and as durable. The existing policy makes kayak paddles an
oversize item resulting in an additional fee ($80 each way). Tour
companies offering kayak adventures supply boats, but not paddles.
Please allow the boating community to travel on your airline as you do
with other sporting activities like skiers and fisherman.