Hi, thought id post the ride report for this board i made a few months ago, Kcasey has sent me a PM to remind me so here it is.
Firstly I made this board as a total experiment and was not really sure how it would go or what the “split” would really do, thought it might create more flex in the tail but to tell the truth my surfing is really not so good and consistent that I can really give total conclusive feedback on a design.
But here is how it went anyway, I surfed the board in small 2 to 3 foot clean conditions ( pictured below) and caught about 10 good waves mainly right handers.
I found myself adjusting firstly to the length of the board, im used to a 6’2", so lots of lateish drops. Once riding the board it was quite fast on rail but seemed to be a little hard to get onto the rail to begin with.
I think the Nose area is too narrow for my liking, wider plan width up front would make for a more forgiving ride and would make catching waves easier too. Quad set up seemed to go ok ( cant be setup as a thruster anyway ha ha) . The split tail did not seem to make much flex difference as far as i could tell however the split did “squirt” water through , slowing the board down I would assume.
My back foot had no problem bridging the gap when getting up and riding, but it was a little off putting having water squirt up under my foot once riding…
Overall it was fun to try but nothing spectacular to report, probably try it again sometime but problem is I have other boards that I want to ride too and surf does not get that good too often…
Heres some pictures(next post if they dont show up first time)
Wow, I know it sucked, but I love
the squirting. I realize that the wave was small, but how high did it
squirt? which portion of the split did most of the squirting come
from - front or back or right under your foot, and where was your
foot? Do you remember if there were times when it didn’t squirt as
much as compared to other times?
This isn’t just my perverse curiosity about squirting boards, Your
design basically took a chunk of prime real estate (bottom surface
interaction) off-line. It’s that “squirt” that makes the
board go. Well, it’s the the upward flow of the water in the wave face
interacting with the bottom that makes the board go.
Really, it’s a
beautiful experiment (and a beautiful board too.) Though I wouldn’t recommend anyone build one, it
would have been nice to have done the same with a longboard to see
how the squirt changes as you walked forward toward the nose. That’s
why I’m curious how the squirt changed with posture, position on the
wave, etc. But don’t worry if you don’t recall, you obviously weren’t
there for my benefit. People do a lot of funky things with tails -i.e. deep swallows, etc., or even deep wings, but rarely are things pushed to this point.
This is the classic planing diagram of Savitsky. The diagram is rotated to reflect the board on the wave face. What is not shown is the forward component of the flow in the face, nor has any attempt been made (here in this diagram) to complete the picture in terms of wakes etc.
Ultimately, the flow encountering by the bottom of the board can be resolved into both an upward and forward components. In order for there to be an interaction of the board with the wave there obviously has to displacement of the fluid by the board. That is, it just can’t sit perfectly on the surface, there must be some interaction with the water.
Also, Savitsky’s treatment is a departure point - it attempts to model the basic phenomena of planing. For example, it’s very likely that not all of the bottom surface contributes equally, and Savitsky’s suggests as much in his pressure profile. But the Savitsky’s diagrammed pressure profile is unlikely to reflect the profile one might find on a surfboard (discussed in prior threads.) In fact, I’m inclined to believe the profile peaks tend to follow the position of the surfer of the board. Yes, that would seem obvious, but it will have some impact on function -i.e. on surfbard (functional) design. Especially if the design doesn’t expect the rider to move much (e.g. short or shorter board, or short or long gun for that matter), or if the design expects him/her to walk around (e.g. classic longboard).
Think of a deep swallow tail - how deep can a swallow tail get before it turns into a rooster tail? (… sorry I couldn’t resist). Okay, that’s an unfair question because it fails to account for the other design features like rocker, bottom contour, etc. …
Surf looks awesome!..I did a north Island road tip in the summer, got good waves…lucked Raglan good for 2 days…first day we were there a f#@Kin massive White Pointer chased everyone out of the line up at Manu Bay heavest shark action I’ve ever experienced… Winter must be a little hard core for cold mind you.
Kcasey, some of the above goes over my head but interesting what you say about how deep can a swallow tail be before it starts to ‘squirt’, I have built a fish just a couple of weeks ago with a similar tail but much shorter split so will post a pic or two an hopefully as soon as I can hotcoat and sand it add it to this ride report.
Soul, thanks,yeah i thought about simply putting a tail patch over the gap, or just one layer of glass and still maintaining the flex…
Marsh, hi yip surf has been pretty good this winter, much more easterly days (offshore on the west and best coast) than usual so the cold water hasnt been as much of an issue as its been pumping! Never seen any sharks at Raglan but im sure they are around, sounds scary, probably didnt stop you going out on the second day by the sounds of it
Yip like the thought, like an onboard jet! it would be worth trying… unfortunately im temporarily disabled, dislocated my shoulder at work falling off a wall so cant even do stuff on boards in my time off, so im glad for swaylocks at the moment keeping me from going totally bored crazy
Think about the jet idea for a minute, that ain’t a rocket or turbine you’ve got there… if it was there would be no stopping you. In fact, if it was turbine or a rocket effect, the faster you went the faster you could go, etc. and you might even be able to catch Roy Stewart - which no one has been able to do to my knowledge. (By the way if you do, Roy will be the fellow wearing the helmet.)
As for pushing the limits of the swallow tail, I love it. But my motives are selfish. Like I wrote in my initial response, your dealing with prime ‘propulsive’ real estate, especially on a short board. But it’s obviously up to you. I couldn’t even get myself to drill some holes in an old longboard to run a few experiments… in someone else’s board sure… but perhaps that has more to do with other matters unrelated to surfing at the moment. (The old longboard market is still pretty healthy.)
… even if you don’t do squat… the ‘squirt’ report was nice…
Senor Kcasey is right, there is no energy gain possible, but considering the loss and turbulence the split tail already makes, why not try to gain tail lift out of it?
Get well soon!!! Take care to let things heal before you jump in the water!!(I know myself…)
Heres the next board im working on, 'split ish ’ tail , just needs hot coating and sanding but could be a while due to my injury…
Hey Soul, regarding the dilocated shoulder, did you have a similar injury and if so how long was it till you were eventually able to surf again? have had lots of estimations ranging from 6 weeks to 6 months so just curious if you have an opinion, cheers
The shoulder is a hard one mate. As it was explained to me it is one of the most complex joints if not the most. So healing is hard to predict. My left one took a reco to get it sorted. But now is great. If you dont want to go the way of the knife (i dont know how bad yours is) you will have to do a strength programe as well as regular physio and you have to be very focused and determined. This can take up to three, six or nine moths. So it really sucks. My advise is go to a sports doctor since you are in NZ there would be plenty of good sports doctors shoulders are one of the biggest injuries in rugby. There is no quick fix just get the right advise and that can only come from a specialist doctor. Sorry to pass on bad news. I think i was surfing after $4000 and about 5 months but it took about nine to get back to full strength. Oh and if you don’t dislocate it in the first 18months after the first time then that can indicate that it is getting repaired or stronger. If you re dislocate before the 18months you will continue to untill you get it fixed. I told you it sucks.
Thanks for the reply, yip its been a week now and shoulder is feeling ok, im hoping that i wont need surgery , like you say though just depends on how well and solid it heals up. Good to hear yours was solid after surgery anyway, as its probably worst case scenario for me at the moment,
In the meantime im going to try a few one handed shapes to keep me busy and productive,
