Fourth Surfboards shank
This curve in the back half gives the board plenty of pivot off the tail which makes it super responsive off the tail, the nose width is pretty wide which balances out the stability/sensitivity ratios meaning the board will keep its mobility at lower speeds and its freedom on rail without bogging or sliding out at higher speeds.
The balance between the nose width and tail width is key to the effortless carves and rail surfing that you can achieve on the shank. The rails are that of a standard shortboard in shape and thickness with harder edges slightly higher up to offer a nice platform off the bottom and plenty of release through turns – the rail and hard edge complement the wider swallow tail beautifully. The added belly channels provide more drive and the ability to push your turns harder which feels good at high speeds in better waves and in weaker conditions when you get the opportunity to spank a section.