14 ft shape proposal

[TWsup]

Hi,

here is my first draft of a shape for a 14ft x 27 allround all ocean board. I have not calculated the volume.
It is modled in Solid Works. It took about 3 hours.

I think the hull shape about 25% back from bow is a bit " belly out" and perhaps not flat enough to be a planing hull. I´ll have to use a different modelling method to fix that.

There is slight V at tail and i tried to get decent constant rocker into it.

Comments welcome.

[TWsup]

I´d also like comment on boxy rails.

some boards are using this some are using a more angled chine idea that narrows waterline making board intially instable and adds secondary stability.

My feeling is the boxy rail will be more predictable in choppy slop an waves that i get in open ocean.

I have also used a bottom rail shape that is a simple round from bow to stern, progressively reducing to 20mm radius at stern.

[Muskoka SUP]

Nice work TW.  Have you considered adding any concavity to the bottom... ?

If you haven't already, you should watch the series of videos that Evan on Standuppaddlesurf.net did with Mark Raaphorst talking about his SIC boards.  There's a lot of knowledge accumulated by Mark over the years that he shares and talks about pretty candidly. There's no black magic involved in shaping a good board .. At least non that he admits to...

Please keep us updated as you go...

Good luck!

[raf]

I wonder if you have enough volume distribution towards the back.  I guess you'd need the center of mass to be right about at your toes? 

[TallDude]

I'm with RAF. With too little volume in the tail, it will dig a hole when you paddle. All that volume up front keeps the nose up, but the back may go under. I paddled some early Hobie prototypes that were similar and the water would circle back on to the cut out deck. The 404's are a little more than is maybe needed, but the tail volume works. Either with width, or thickness.

[TWsup]

OK- more volume in tail and watch that displacement on the bow.

Where would you put concave ? My Fanatic AW 9,2 has concave on Bow and this obviously helps on wave take off and planing.

I need to figure out a way to calculate Center of Boyancy.

Is deck cut out too much ?

[raf]

how about making a shorter cockpit where you stand (with a scupper at the aft end on each side) and then eliminate the cut away deck in the back 3-4 feet. 

[Pierre]

Nice job TW. ... my opinion is that you should  reduce flotation width behind the nose and add width  above flotation line. so your bow wave will create lift in DW conditions. For a 14 footer i don't see any interest of adding volume near tail.
be careful to calculate flotation  ( waterline) vs tour weight + estimated board weight to see if not too high or too low above water... . heavy paddler= wider, more rocker...
attached my ideal bow shape . chines help for planing...

[Pierre]

..and don't forget you mat stand near tail to ride a wave!

[Pierre]

 another sketch about concave effect for planing ability. on a 14 footer concave between middle and 1/4 tail is great. legends in french but easy translation I guess ;

[TWsup]

Made some changes:
less volume in bow- took away guppy look
More rocker tru middle and stern
Thicker all the way thru towards stern
added flare to sides as suggested for wash and secondary stability
Better deck cutout

Volume 310 liters- see pic for COB

I can try the concave stuff another day- i have the model built a good way now and have more control.
Dont have real naval architecture SW. Only Solid works

[Pierre]

My opinion is that it can be nice shape but those rounded rails without chines do not give much planing ability if you expect to take opportunity of some downwind conditions.

hard chine  create extra lift for planing.
additionally i don't understand why you don't make a vertical stem on nose. Even in average DW condition this is not a problem to control.

with those rounded rails your board is more a flat water/ lake shape and in that case a vertical or wave-piercing stem is welcome.
if more ocean going/ DW, this nose shape can fit, but hard chine at rail bottom will help more for planing.Look at-and try- same race board with deep stem. not so difficult once stem out of water. and easier in upwind chop.

[TWsup]

Pierre, thanks for feedback.
I'll put some chine and try concave on next version. I was looking at new Fanatic Falcon and it has rounded rails.
also will look at vertical bow.
basically having trouble with Solidworks that has some limitations. or my knowledge of the sw is not enough. 

[Henrik F]

Hello there! I haven't seen this before. Is there an update comming up soon?

Henrik F

[RainWaves]

 Interesting thread that I too have missed.

 It looks like what you (TWsup) have come up with is very similar to the front half of the 15' SIC custom that I got this Summer: