Board outline, with and without fins

[nomastomas]

Camo shark proof?

Pondering what board to take to the Pacific Northwest next week... the Bonzer Paipo or the Orange Matter (Baseline Austin). Thinking the baseline Austin since it has more float than my bonzer. All that rubber stuff adds up in tonnage! Gives me more time to contemplate my slide angles. I do like the drive from the center fin on those PNW waves

Here's one of my customers riding a "full-bodied" 51" TB1 at the 49th parallel in the summer. Float is a good idea....

[rodndtube]

C Street can be a very nice break. Only have ridden it a couple of times but the best was actually about 33 years and one month ago (late June 1982). From the peaks all the way down towards the pier. Like you said it wasn't a Pipeline type wave but I do like those long walls for carving, turning, coming off the top, blah blah blah. Looks kind of crowded in the photo above and the other couple of times I have seen it.

Simple is straight rails should be the fastest? Tear drop shape is technically slower but also holds into the wave better. Wide tails (guitar pic HPD style) can be fast but also very loose. Where would you put the fins on a board with nearly parallel rails with no discernible hip in the board. Of course, it is all a series of compromises because I probably would not like the "fastest going straight shape" as one can generate speed off of maneuvers and use of the skegs.

[JJJ]

Was watching a Greg Daniels video on youtube; he takes water shots/video at various spots on Oahu. Mostly shorebreak. The following link is a video of a fun day at Makapu'u: https://www.youtube.com/watch?v=OQfv0x-4nqU

There are a couple of underwater shots of body boards going down the line that gives a clear view of the boards planing surface in contact with the face of the wave. One in particular stood out at 4:18.

If anything, it's a cool video to check out.

[bgreen]

Nomatomas,

I asked Larry Goddard about his thoughts on your questions. He liked the analytical approach adopted and his comments follow:

"I think the Yaw angle of a board on a wave depends on the steepness and breaking or Peeling Speed of the wave a lot, in addition to the outline shape of the board, and
the speed of the board across the wave face. All the boards I designed for myself to ride in big, fast Point Break surf had skegs, so had a minimal Slip Angle, or Yaw.
I started out on the flat-bottomed Paipo Nui, which had a tail that was much wider than the nose area, giving the outline of the board at the rails a sort of
triangular outline profile. That makes the centerline of the board point inwards toward the wave face when you are in full trim going across a wave, BUT, when you
lift the rail up in the air to carve a turn, the centerline of the board then points in the OPPOSITE direction of your intended curved path! It's dynamically UNSTABLE!
It fights you when you want to change direction, as in a cutback. That's why most paipo riders just prefer going fast, in a more or less straight line. But, that's
all right; they're all 'SPEED FREAKS', anyway! That's why I started designing and shaping my own belly boards: I wanted to find a shape that would make it easier to turn, yet still be FAST enough to make most waves.

I decided on the best 'slip angle' to design my board for, and made the nose wider, but with the tail only slightly narrower than the width at the Wide Point. The
result of testing my designs in fast Point Break Makaha surf (10-15'+, mostly) was that the tail width was about 3 inches less than the width at the widest point, with
the Wide Point a couple inches forward of the Center Point location. The slip angle of my boards (with the skeg or skegs installed) was only about 6 degrees, at most.
The mathematical curve that best fit those requirements was the Exponential Curve. That is what I used on all my High Speed boards. 'Hot dog board' shapes use a more Elliptical outline (or Plan Form).

I don't care for the skegless 'slip-'n-slide' feeling of bodyboards, or even wide-tailed 'Guitar-Pick' style paipo boards. Oh well... it's all relative."

Swaylocks might have some interesting stuff:

http://www.swaylocks.com/groups/theory-balance

From a pronish perspective Rod saved a lot of Terry Hendrick's stuff.
Bob

[bgreen]

Poobah,

boydboard + drone footage

Lots of hits.

Bib

[krusher74]

I have also surfed Cstreet on my travels an would put that wave in the middle ground of waves for shape and power.

Today I was on in uninspiring 2/3ft onshore beach break conditions. I took out my BZ retro boogie board (retro is the model name) it very wide nosed and tailed with a very straight template the wide point is forward of middle http://www.wireplanet.com/ecom/stores_a ... 0large.gif

This is the boar I use in less than powerful conditions. I notice today on awave that went very flat on me that to keep speed I move very far forward on the board at one point till my knee caps are on the back corners of the board. I fellthis is to move up till weight is over the wide point. This board in its straight template is very fast ,but slow an hard to turn with its lack of rail curve.

I put this board forward as about as straight railed/wide and wide point forward as anyone would need (unless they just wanted to just straight line a wave.

I took it on a trip to G-land one year as an experiment and once the wave was over shouler high it was out of control,I see it as my minimal paipo. (I call it "the log")

How do you think its angles fall in your study nomas?

[SJB]

Krusher wrote: "I have also surfed Cstreet on my travels an would put that wave in the middle ground of waves for shape and power."

Here we go again with a "generalization". Since C St. is 30 minutes from my door to shore I look at it daily on the web cam....and some days it is weak and I don't bother. Medium days can be lots of fun.....and on power days I typically don't go. It can run the gambit....again....depending on too many variables to list here.

Rincon is 20 minutes from my door to shore.....I would also rate that as somedays too weak....somedays just right....and somedays too powerful FOR THESE 69 YEAR OLD BONES. Send me some youth!

This time of year C St will get some south swell action....Rincon seldom. Winter north swells will typically get into both but here is the deal....Rincon can be a cluster F given the crowd and demographic. C St. has more take off locations which can make it less agro and more fun.

Having said all of this....when both spots are too powerful for my old bones....there are several less traveled spots that give me all the action I can handle with a smile on my face.

All of this is to say I thank my lucky stars each and every day that I live where I do. Come on out....but don't stay too long.

[krusher74]

Krusher wrote: "I have also surfed Cstreet on my travels an would put that wave in the middle ground of waves for shape and power."

Here we go again with a "generalization". Since C St. is 30 minutes from my door to shore I look at it daily on the web cam....and some days it is weak and I don't bother. Medium days can be lots of fun.....and on power days I typically don't go. It can run the gambit....again....depending on too many variables to list here.

Rincon is 20 minutes from my door to shore.....I would also rate that as somedays too weak....somedays just right....and somedays too powerful FOR THESE 69 YEAR OLD BONES. Send me some youth!

This time of year C St will get some south swell action....Rincon seldom. Winter north swells will typically get into both but here is the deal....Rincon can be a cluster F given the crowd and demographic. C St. has more take off locations which can make it less agro and more fun.

Having said all of this....when both spots are too powerful for my old bones....there are several less traveled spots that give me all the action I can handle with a smile on my face.

All of this is to say I thank my lucky stars each and every day that I live where I do. Come on out....but don't stay too long.

For the sake of the topic of this thread its runs the "gambit" of on its average day a medium wave in my opinion, so I will stick to that "generalization"

How about your opinion on board outline compared to wave shape? (sending you some youth )

[SJB]

Apologies for my uncalled for outburst Krusher. Thanks for taking it in good humor and sending me some youth. As a generalization I will accept your C St. observation. I have 55 years time in grade in these waters and I love them and I got a bit defensive. Fact remains....on some days C St. can be powerful.
Now...as to the angle of the dangle....look back and you will find I already put my two cents in on that subject earlier in this thread. You will see I have the "generalization" theme on the brain. Not very technical but with a playing field that is constantly in motion and flux how can there be an exact answer to such a question?

[rodndtube]

<snip snip>
...You will see I have the "generalization" theme on the brain. Not very technical but with a playing field that is constantly in motion and flux how can there be an exact answer to such a question?

Yup, that is the biggest challenge. Not only the playing field being in constant motion but in many cases the rider as well. The danger is maximizing one board attribute with the unintended consequences of diminishing other board attributes. Nonetheless, it is fun and can be rewarding to walk/ride down this path.

Off-topic for this thread: The old brain does numbers on me at times, too, oh, all too frequently! Sometimes, if it is weaker at a given break it forces me to say something stupid like it is only 2-3 ft instead of 4-6 ft. But on-average, Rincon (Calif.) and Fairgrounds/C-St, break rather well with their nice stable point break qualities, even on less favorable surf condition days. The crowds and behaviors... that is a whole different story in "rating" wave/spots.

[nomastomas]

Great to have Larry G's input on this matter. However, I don’t understand what Larry means by his statement regarding WP back outlines “That makes the centerline of the board point inwards toward the wave face when you are in full trim going across a wave, BUT, when you lift the rail up in the air to carve a turn, the centerline of the board then points in the OPPOSITE direction of your intended curved path! It's dynamically UNSTABLE! It fights you when you want to change direction, as in a cutback. “ Can someone clarify for me?

[krusher74]

Great to have Larry G's input on this matter. However, I don’t understand what Larry means by his statement regarding WP back outlines “That makes the centerline of the board point inwards toward the wave face when you are in full trim going across a wave, BUT, when you lift the rail up in the air to carve a turn, the centerline of the board then points in the OPPOSITE direction of your intended curved path! It's dynamically UNSTABLE! It fights you when you want to change direction, as in a cutback. “ Can someone clarify for me?

When Larry is talking about WP back outlines I think he is being specific of these shapes only http://www.d-talks.com/wp-content/uploa ... Centre.jpg

[bgreen]

Nomatomas,

Here's Larry's comments:

" The Friday posting by "nomastomas" was actually already answered by "krusher74" in today's (Saturday, 25 July, 2015" posting. I was commenting
on the handling (turning) characteristics of boards that have the Wide Point (WP) located BEHIND the Mid-Point of the board. The most extreme
example is the original Paipo Nui from the early-mid-'60s, which used the traditional 'guitar pick' style outline shape or design: widest way back
in the TAIL area, as opposed to the more traditional "Tombstone" paipo board shape (round nose, more-or-less parallel rails, square tail), which
is not quite as fast, but is much easier to control and maneuver.

Take a look at the Paipo Nui, designed by John Waidelich, and produced by Val Valentine: Now, imagine laying this board down on the floor of your house. Line up
the centerline of the board with a line on the floor. If you then lift one side of the board so that the rail edge line is still on the floor, you
will notice that the direction that the centerline of the board is pointed has shifted and is NOW pointed a bit to the side OPPOSITE from the
direction you want to turn towards. All this means is that you need to turn on the corner of the TAIL, not on the rail of the board! You have to manhandle a BIG paipo to do that!

That's how Harry Akisada does it at Makaha in overhead surf. The nose is in the air... most of the board is in the air. He is carving
water-skier-size 'Rooster Tails' from the corner of the super-wide tail. But few paipo riders of that wide-tailed design do that, preferring to
just go as fast as they can. If you want an easy-turning board, then the outline of the board need to be narrower in the tail area that at the wide point, and the WP will end up a little forward of the mid-point of the board."

Bob

[krusher74]

Nomatomas,

Here's Larry's comments:

" If you want an easy-turning board, then the outline of the board need to be narrower in the tail area that at the wide point, and the WP will end up a little forward of the mid-point of the board."
Bob

I also notice that Larry's conclusion of the bullet points of a easy turning board are what bodyboards have been since there invention.

The second picture is the shape (at the extreme end of the scale) of a Drop knee bodyboard where the rider has all there weight on the back half of the board, these riders seem to prefer the wide point back from centre. Which I feel would suit a prone rider who likes to ride with the weight to the back corner of the board and maybe over a rear fin like in Nomas's designs.

Do the angles in these designs in context to this thread differ by more than a couple of degrees?

[rodndtube]

Now complement this discussion with the Vektor bodyboard fin system for dropknee riders.

[krusher74]

The BZ maligs board also had fins pretty far up in the 90's , hmmmmm totally confused now

[rodndtube]

The main point on the Vektor System's asymmetrical fin placement was placing the fins underneath the dropknee rider's weight (pressure) points for the foot and the knee. I might add that my Bonzer paipo has runners further forward on the board than my regular Austin placements.

[jbw4600]

Thomas, To answer your question about yaw angle. In very steep surf I think my yaw angle is minimal (0-5 degrees) when cutting across a wall. And with no fins it would be even less in steep waves. When ridding finless (which haven't done for a long while), I tend to dig the front rail in hard when cutting across a steep wall. But even with fins I tend ride the front rail quit a bit. That is why I like boards with the wide point forward of the midline. I always wear out the elbows of my wetsuits. When the wave angle goes down or the line of attack changes then I think the angle will increase. But everyone has a different style of ridding.

[davehahn]

Fascinating thread. I'm learning a lot.

I might just throw into the mix, if it matters, that the angle of yaw may well be 5-degrees or 12-degrees, but it's not positioned off the center line. The wave face hits a larger area on the board, as in the graphic attached. I think this difference is significant, as it brings much more of the B&R and outline into play.

Bodyboard_Mach_7_7.jpg (19.32 KiB) Viewed 3393 times

[nomastomas]

Your absolutely right, Dave. The Daniels video submitted by JJJ was quite revealing in this regard. I've been dealing with the summer rush and haven't taken the time to respond to all the great input here. I'm working on it, though...