While surfing the Hook, I watched a little grom flying down the line so fast he looked scared. He was riding a 5'2" Source mini hull/Simmons, a bit short for his power as he was getting bounced around a bit on his line. The board and rider were very fast in the lined up walls. I talked to Nick Saturday (who had the board with him) and we went over his design aspects and the whys and hows.
I took a template off the board and got the rocker numbers and fin placement. Nick mentioned he moves the fins up a bit as the length increases but he doesn't build them longer than 5'8" I think. (on edit-he goes up to 6'6" with these 'Scrambler Models).
The fins were made just for that board design, not a keel or a D fin but more like a traditional thruster fin but with a longer base. Single foiled and toed to 9 degree's (thats a guess). I started on one yesterday as a kneeboard shape for me, 5'6" by 23" by 2 1/2", 20" nose, 19" tail, flat hull to concave through the tail. If I don't like it, it will work as a stand up rider for a chipper who wants to go fast.
There is no explaining how fast these little boards are. I did a go behind on a logger at 38th st. and played in the pocket behind him till I saw he was going to get left behind. I dropped back in hard with all of my weight forward and swooped around him in a long sweeping bottom turn, aiming for the top of the section that was closing out in front of us. I threw the board up, set the down rail and was back in the pocket in front of a ten yard section while the logger was trying to figure out what happened.
Its the speed off the pump and the subsequent glide that opens up different lines and 'feel'. There is a lot of 'feel' in these shapes.
Like skating a pool.
After I finish my kneeboard, I am dropping my length down to 6'2" and my width to 22", staying at 3" thick for float and paddle. Nick mentioned that I didn't need so much 'flip' in the last 4 inches of the nose hull but I think it helps in paddling in to waves. I can get my weight far forward without digging the nose in. It might help in duck diving, I was able to get good penetration on my sixten when I went under a few 5' walls at 20 seconds, some push back but I was able to paddle through fairly easily for a board thats got a lot of volume.
I put a link up to Nicks' "Source" label, I highly recommend them, after seeing how fast that kid was going, I can only hope to shape a board that goes that fast down the line.
Here is the board I saw at the Hook...
Oh, he uses a disc tail for a bit more drive and lift, something I am going to do with my kneeboard to see how it goes.