Custom built aerodynamic shaped, Epoxy Composite Mast - Sail Quiver Box.
Hand built in Belgium in 2008 exclusively for windsurfing because I got tired of having no room in my car for anyone else to go with me due to the car being otherwise packed with windsurfing sails, masts, etc. Using the box I can carry 6-7 sails plus masts inside freeing up my right front passenger seat and lots of extra room inside the back.
The quiver box was four months in the making using epoxy, glass, and some carbon fiber, over a 4mm wood core. It is 10' long overall with 9'6"of inside usable space. It will carry sails up to 11.0 and masts up to 530cm long inside. Amazingly for its size it is only 38 pounds empty weight! Compare that to the 45-60 pound Tule and Yakima roof top boxes which are at least 2 feet shorter in length!! The rear rack attachment brackets can be extended to lift rear of box up off the rear roof rack allowing the car's rear hatch to fully open.
It is currently set up for the round bar Yakima racks with a 5' spread between front and rear racks. However, the box attachments can be altered to fit other rack systems.