Even after finding a kayak friendly airline, make sure you aren't taking any connections on smaller planes.
Last year we had everything worked out to pay an extra $80 to United to fly with our boats to Costa Rica but they changed our connection flight from Denver to Phoenix to a smaller plane that we couldn't take our kayak on.
Just flew with US Airways (are they and United partners?) to Costa Rica and it was pretty easy. $80 for up to 8 feet and 100 lbs.
Frontier is real easy for domestic. Supposedly American and Delta are really difficult, but a friend just flew with American from DIA to San Jose, CR with a ZG that he covered in cardboard and they took it.
My best advice would be to do plenty of homework and as Scott Lindgren says, "Don't take 'No' for an answer."
I have found that if you box them up and tell them it's extra stuff they just charge you 75-100 $$ more. united and alaska are the best I have found. If you tell them that its a Kayak they seem to have a problem?? I took a trip 3 years ago to mexico via Alaska air the hard part was the busses I had my backpack, boat, and paddle standing in the middle of the bus for 4 hrs by a chicken and 100 other people that smelled worse than my drytop. Plan smart not cheap (like me) and have a great time.
unless you are staying a very long time, you might want to consider renting. last year I had my boat at the airport (boxed) and couldn't get it on the plane (United). e-mail Small World (www.smallworldadventures.com I think) and you can get a list of available boats and prices up front and then decide.
thanks for the info, sounds like Delta is a bad choice, but they are the cheapest tickets. Has anyone done the "surfboard equipment" manuever with Delta? I don't feel comfortable leaving it up to a roll of the dice.
Delta was a sponsor of the '96 Olympics and they broke some race boats owned by the Czechs. Word is that Delta still thinks of kayaks as 12 feet long and fragile, and that they are awful to deal with on the issue. I would not chance it with Delta personally if I was flying with a kayak.