2-3 foot. I surfed a split single board today, Mark Ograms take on Neil Purchase Jr's Duo. It was a sick board. Fast and drivey and really positive, with surprising release off the top and a penchant for going vertical. I let a mate have a ride and after his three waves he reckons he is buying one. Oggie better make Prototype 1,2 and 3 quick smart as I think he will be selling a few of these if people can get over the look of the fins. I used my 7 1/2" Wayne Lynch fins in it and thought it would be horribly overfinned (it was a 6'9") but it was so loose when I wanted to release a rail. Sick sick board. I'll be borrowing that again when we get some decent surf. Surfed sort of like a quad would if they turned properly.

really loose out of the lip. Up down up down up down. Three or four turns in each wave. There was a bit of morning sickness still around so it wasn't barrelling properly, but the one wave I pulled in on it washed speed off well too when I stalled to backdoor the section. I didn't make it and got clamped on, but that was the wave this morning, not the fault of the board.
6'9"x22x2 7/8 and it felt like one of my HP shortboards - better. Mark basically shaped his favourite single fin board (rocker, bottom, foil, dimensions, nose outline) and widened the tail. It looked really weird to my eye and I was pretty dubious, but I'm almost sold. Just want to try it in 4-6.
My mate has been surfing the same board for three years in 0-8' so for him to say he wants to buy one...