Hobie 21's have curved beams. The one Loyde and Louie built had the same curve.They were very nicely done. Anadized black. They were used for one midwinters and I don't know if they were used again. The problem with a 12' wide 21 is that when you get powered up enough to fly a hull the nose wants to dive. I wish I had a video of trip Louie took doing a full 360 around the boat on the wire.