Jun 26

Tail shape and bottom shape at the tail

You can’t come from a background of non-cooperation and then “poof” proclaim you are cooperative. You bring zero credibility to that discussion. Water doesn’t cooperate, it always resists and seeks it’s own equilibrium. It’s forces are always opposite to whatever is pushing against it.

Have you ever looked at pictures of folks riding as they come in on bottom turns and off the lip on top turns? Where is the board in contact with the water?

Here are a few select pictures, bottom of the wake not really driving forward, but gaining speed from the wake face. Notice the areas of the board that are engaged with the wake, or the water.

backside pictures 235

It’s really hard to see, but the outside fin is mostly out of the water. The only part of the board that is engaged is the wakeside rail.

backside pictures 238

Everything from the front foot forward is out of the water and across the spine. The outside rail, the one closest to you in the picture, is also out of the water. Try and visualize the contact area of the water under the board.

backside pictures 239

Very tippy, top of the spine and virtually everything in front of the front foot is out of the water. Only that area from just about the fins back is engaged.

backside pictures 240

What part of the rails are engaged at this point? We know it’s really hard to see because of all the water splashing around, but it’s nothing in front of the fins. You kinda have to draw an arc on the lip and see where it intersects the wakesurf board.

backside pictures 241

Here is an unedited picture at the very bottom, in trim along the bottom of the wake.

backside pictures 246

Here is that same picture and we’ve marked up the intersection of the wake with the bottom of the board. This is with the board in trim, pay careful attention to where the contact area is.

backside pictures 246 marked up

Did that open your eyes? It really should. In trim, where we are just hanging with the wake, there isn’t more than 10% of the board that is engaged. But here is the really important part, as speed increases and the board is being turned, that area is smaller. Also, the only area of the wakesurf board that is consistently engaged with the wake is that area of the tail behind the fins. Even then, often times the outside rail and fin are not engaged with the water.

We’ll leave you with a question. We talked yesterday about the speed of a wakesurf board as it’s traveling down the face of a wake, but do you have any idea how fast the water is traveling up the face of the wake? We still have to fight the spammers and the concept of push, but the reality is that water is rising, it’s a lifting force. If the rate of travel of that water was faster than the speed of the board as it travels down-the-line, that’s where we’d want to focus our shaping efforts, isn’t it? Moving that water around to prevent drag would prove to be the most efficient wakesurf board design, wouldn’t it?  What function do full length concaves and channels provide in that instance?  Is there a channeling effect of water down the middle of the board?  Really?  Can you reconcile that with the picture above?

Thanks so much for following along, we really appreciate it.

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