The seed of this idea was the Maurice Cole/Tom Curren reverse vee boards of the early 90s.
Allan Gibbons revisited the design a few years ago and has been developing it ever since, most recently with Kauai ripper Bryce Baker.
This alt-step up has slight vee in the entry, turning to flat at center, to slight single concave between the fins, with an accelerating tail rocker.
While it packs some volume in the center, it has low, smaller radius rails for knifing in.
From 6'2'' to 7'0''
Wide Point: 19 3/4"
Thickness: 2 5/8"