@ReForest
ok, let’s go back. I said that the double diamond tail is basically a swallow tail, and the wings release water helping the board turn.
I quoted someone who has built countless boards that there’s only a handful of tail shapes. Maybe more than 3, but basically round, square, swallow. If you want to add pin and diamond to that i can see that.
the tail is a tiny part of the equation. The width of the tail on the other hand is very important.
so, if you put your round tail Hydroshort on top of the squash, I would imagine that you would see how the outline stays straight on the square and curve pulls the round tail in.
the OUTLINE changes BECAUSE of the tail shape. so, yes tails matter but the outline is more important.
for example a wide round tail will plane faster than a narrow square tail. The tail isn’t making a difference in that case, but the wide outline is.
does that make sense?
edit: fwiw I don’t make boards anymore but did for a long time with a lot of amazing people.