RE: iSonic length question
Look the other way !
No, seriously ... As the volume increases, they get wider, which increases the available planing area/surface area at the back end of the board - which in turn allows a shorter, lighter, more responsive and faster "short front" board length to be configured. (iS133)
The short wide outline delivers the highest efficency (aspect ratio) planing surface, but there is compromise towards control at higher speeds, rougher conditions.
Alternately, at high speed, we need a increased amount of compromise towards control in the ideal "optimum mix" of theoretical efficency vs real world speed, which narrows the board (planing surface) - and forces the planing area narrower but longer to still retain the required surface are for that board configuration. (iS87)
Cheers ~ Ian