Depending on your airlines "policy" re: windsurfing gear, they may not count any of your gear bags as
"luggage" in your 2 bags per traveler scenario.
My last trip I took about the same amount of gear, Continental Airlines.... Newark, NJ to Bonaire NA and the cost was $850 USD for the WS gear.
I had it all in 3 bags.... 2 boards in a double travel padded bag..... booms, small sails, harnesses and bases etc. in a large boom travel bag..... masts and large sails in the 3rd long sail.mast bag.
You can never tell what they are going to take as luggage and what they will charge.