Hopefully there are some kind soles out there willing to give me a hand with fin placement on my first board. I am currently as far as designing it in Shape3D before getting to work over the holidays. The goal is a higher volume easy to use Performance Fish similar in thought to something like the Firewire Seaside Model, maybe a little less performace and more fun easy surfing. I have kept the bottom contours very simple with a slight double into V through the tail, as it´s my first board designed and built from scratch and I don´t want to over complicate it.
Attached where my first thoughts for fin placement. To be honest they where a bit of a researched guess based on a bunch of numbers people have already been kind enough to post. But at the end of the day each board is different. The idea is to keep the tail as it is. If I change anything I would maybe put in a very slight dimond tail maybe (1/4 inch). Fin placement I have currently placed 5 boxes but I think I would be happy with 4 especially if I can get it set up switchable between Quad and Twin. I know there are probably a number of mistakes and the board might be a total dog so I am happy on any feedback even if it sends me back to the drawing board.
That looks pretty good. Nice overall design. The placement looks like it will work fine. The alternative would be to move the side fins forward a bit. If you were to leave the two side fins where they are in relationship to each other, but move each side forward say half the length of the center box. Just a possibility that I think might loosen the board up a bit. The fins are in good position with the rail and the Toe looks very good. My personal preference is to not cluster them quite as much as you have. PS Shape 3D sure is nice. Wish I was that smart and techy.
Good job. Just a few comments. I think the middle rocker looks too flat. Perhaps a little more continuous curve? On the fin placement, it’s always a compromise when deciding twin or quad. If you build quad and decide to run it as a twin the fins are going not going to be in the optimum position. You can overcome that to some degree with fin size (which will move the center of lateral resistance fore or aft depending on fin size and shape).
I’m not a fan of quads simply because I don’t see waves of the size that need that much fin area. I like twins with a small trailer when it gets bigger. More stability. Have a look at Mark Richards twins to see what I mean. Also, five fin boxes add a bit of weight at the tail. Not a big issue, but if you are pinching ounces on the glassing and then add 5 fin boxes…