With respect to Herbs work.
My eldest son and I have been making vents thru boards to create lateral control, theyre not designed to draw air down but to redirect water up from under the board.
Similar to Herbs work but mine are longer and asymmetrical and provide control specifically to replicate the feel of a standard finned board.
In a week or so I will have pics of them in boards but for now I have a few pics of the construction and prototypes.
I didnt shape a board and then shape a hole in it. I shaped the 'void' or vent and used it as a molding plug to laminate the walls of the vent.
This is the size of the original mold showing the hull or induction opening, the straight edge goes towards the rail.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/August2010008.jpg[/IMG]
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/August2010010.jpg[/IMG]
Some of the shape and size variations for the hull vents.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010024.jpg[/IMG]
Finished vent plug.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010003.jpg[/IMG]
Carbon fibre layup, it looks thick, but its got a lip around the edge.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010010.jpg[/IMG]
Off the mold and you can see how the water flows from the hull thru to the deck.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010011.jpg[/IMG]
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010012.jpg[/IMG]
In testing the effect of this design proved to be too strong and some of the internal wall angles werent right. But we found out that it can be smaller and still comparably effective as a standard side fin.
This is a much better and compact version. Because boards arent very thick near the tail the tube itself only needs to be about 1.5 in high.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010017.jpg[/IMG]
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010015.jpg[/IMG]
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/September2010019.jpg[/IMG]
It has the deck and hull vent overlapping so the flow is quicker and the whole unit is smaller.
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/SeptemberB2010006.jpg[/IMG]
Better version of the plug mold.....
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/SeptemberB2010005.jpg[/IMG]
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/SeptemberB2010004.jpg[/IMG]
[IMG]http://i153.photobucket.com/albums/s225/SURFFOILS/SURFFOILS%202010/SeptemberB2010007.jpg[/IMG]
The vent/tube/port creates control in the same place that standard fins are placed.
We're only focussing on making something that could be put into a standard glassed board instead of fins.
More pics if you want.
Anybody else following Herbs lead ?