I'm sure most of you know this by now, but I figured I'd post for those of you that don't. I just got back from Tamarindo, and Delta charged us $300 each way for each of our board bags. Ended up being $600 per bag x 3 bags for a grand total of $1800. I had no other checked luggage. They continue to handle golf clubs, snow skis, javelins, vaulting poles, rifles, etc. free of charge. I think an out and out boycott of Delta by the surfing community is in order.
There was a 14 year old kid with his mom at the delta check-in desk in front of us in Liberia who flew a different airline from boston to CR. When the delta rep told her what the board fee was, the poor kid had to go sell his board to some ticos in the Liberia airport parking lot for 20 bucks because they couldn't afford the fee.
We took a similar trip around the same time last year, and were forced to fly delta on the return due to a flight cancellation and were charged $175 per bag. Pretty stiff increase in a years time. My brother flew all the way to New Zealand for a trip last year and was not charged a dime by Quantas or New Zealand Air for his boards.
I hope this prevents someone else from having their budget wrecked at the outset of their trip.

The surfline link breaks down fees for each airline. The second link contains an online petition.