hull rocker: rocker/rail line/sweet spot

Haven’t even ridden my fish yet and already obsessing on the next project. I’m posessed. So I am designing in my head and on aps3000 and am hoping for some clarification from the hull experts.

One thing I have not found in archieves is relationship between rocker and sweet spot. I now know, deepest part of hull is where the sweet spot will be.

Thruster sweet spot is where back foot goes (if you had to put an X)? So is hull sweet spot where front foot goes?

And if you move sweetspot rearward (deepest part of hull) then should you carry the curvy part of front rocker back as well? So maybe front foot/deepest part of hull should be at or just behind where rocker (at stringer)" breaks" from flat to curve? )Carry the rocker back and then adjust the rail line rocker w/ “rail bands” so deepest part of hull matches that transition in stringer rocker)?

Hope this makes sense! Many thanks!!!

ive found my sweet spot to be where the depth of the hull is deepest, the rail is at perfect 50/50, and the rocker transitions to flatter from the nose kick…it doesnt create and EXACT spot, rather the space that sits between your two feet as you trim, as an area…if that makes sense…

ive found my sweet spot to be where the depth of the hull is deepest, the rail is at perfect 50/50, and the rocker transitions to flatter from the nose doesnt create and EXACT spot, rather the space that sits between your two feet as you trim, as an area...if that makes sense...

Perfect sense. I’d imagine this would best be built at the wide point and as you move the sweet spot (deepest hull/rocker transition/etc) back you would want to also move the wp back. All that will then shorten the turn radius while keeping the drive. I’d also imagine, that in this progression you would gradually loose some trim speed and when it was all far enough back, the fin would no longer release and you wouldn’t really have a true “hull riding” board anymore.

I’ve made really nice “hulls” with a parallel outline, wide point up around 6" from midpoint and the deepest part of the hull is just in front of the fin. You just surf it from a futher back. It still gets up on a rail and stays there (drive). Just a different feel, you can jam a turn without spin or drift.

I’m not sure how to explain this so I’ll just take you through my process. Dennis and Spence will cringe I’m sure.

I rough in a basic hull rocker: 4-5" nose and 1.5 to 1.75" tail lift. I put this rocker into the bottom from rail to rail so the bottom is dead flat from rail to rail but rockered from nose to tail. Then I decide where I’m going to put the “hull”. I take a hand plane and cut a rough rail rocker notch in the intersection between the outline cut and bottom. I cut it to the depth of hull minus some to account for the bottom rail radius.

Then I smooth the rail rocker into a nice flowing curve. Now you can bring in the heavy artillery and cut you bottom bands to blend the rail rocker rough cut to the stringer. Smooth it all together making sure that you have a nice flat bottom contour behind the fin. If the “hull” is back, then you will add a gentle kick to the overall tail rocker.

The futher up you put the “hull” the less dramatic the tail rocker will be. I would not pull the nose or entry rocker back or you will take all the glide out of your ride! If you move the wide point back you will take away rail line from your turn and the board will lose some drive.

The key (and to me the most fun) part of shaping one of these boards is blending the whole thing into smooth, flowing curves…I like to think like water when I’m sanding the blank.

If the "hull" is back, then you will add a gentle kick to the overall tail rocker.

Nice! This is MUCH more clear! That added tail kick is all the way across, stringer to rail and not just rail line rocker?

Just a different feel, you can jam a turn without spin or drift.

So this would be the shorter radius turns and you can engage more rail and make the longer ones as well???

  1. Yes, all the way across.

  2. They are all relatively long radius turns if you use the rail. You can push a shorter radius turn with less rail but you won’t drift or spin like you might on a Liddle. My boards do not have that organic, “Its alive!” feeling Liddles have. You have to surf the board unlike a Liddle where the board finds the speed line with minimal input. I have to roll it up on a rail on a Liddle. On my board you can snap it up on a rail. I feel like I am surfing the fin more on my board whereas the I feel like I am surfing the rail more on a Liddle. Since the rails and outlines are pretty similar, I think its a function of the “hull” location and that little 1/4-3/8" kick in the tail rocker.

LeeV you are a prince! This is really starting to come together w/ old rusty memory traces of some boards I had in '70’s and ways I tried to ride them and fin them that never quite worked out and now I see why.

Somehow I’m getting an image of Al Pacino in Scarface where he buries his face in a pile of white powder and comes up, eyes bulging saying “Let’s get organized!” Only in this case the powder is foam dust.

Couple other questions but will save those for a different topic thread but

Smooth it all together making sure that you have a nice flat bottom contour behind the fin.

Only flat behind fin? Rest of board the hull part is blended all the way to stringer on your boards? I imagine it is doable but rides differently if steeper curve to hull allowing some flat down the stringer for more of the board then just tail???

Now I’m thinking I’m going to make 2, same template and rocker one w/ sweet spot at wp and one just in front of fin. Gotta do it.

Huh? You lost me…

Yeah, I was afraid I might be a bit incoherent there. Lets try that again… the rail bands on the bottom of the board could carry curvature clear to the stringer or, for the same rail line be steeper and leave some flat area in the center. Is the whole bottom convex or are there flats crosswise direction? If flats, do they move to different place when you move the deepest part of the hull, or…??? Ulp, is this any more clear?

I know people make them all kinds of ways but I guess I’m looking for suggestions from experience on what seems to work well.

Once I had a board shaped by Rick Hammon. A Hammon egg funny yeah? Had roll all the way back and a big single concave from wp all the way back. Went great in small North County San Diego waves

I’m wondering along in the same train of thought though, DS. There’s a shot of Andreini shaping the bottom of a stubby in the TSJ Stubby article and the center is flat, and he looks to be blending into that flat from the sides. Shot of Bojorquez holding up a hull in profile seems like the bottom is pretty flat, and Liddle seems to be saying he’s using more flat now on his website. I was thinking to make the flat on a future hull as wide or maybe a bit wider than the length of my feet, and the rounding pretty slight toward lower rails. Conditions here demand adaptation toward planing.


Janklow, yes! So, deepest part of hull calls for most curvature. If it is forward, in wider part of board that curve has more room to spread out and be gradual and even then leave room for some flat in the center. Or no flat? If deepest part is back where board is narrower AND you are more interested in planning aspect of function (?) if you want to leave flat in center, you need steeper curve out towards rails???

I have a longboard that would almost all make sense as a hull (not the length, pig hips, not the concave nose, not the fin box placement, and not the squared tail), and in that article they say that longboards by the classic guys were the inspiration–but then the things became much more specialized and almost zen tools for a pure experience. The corners of square tails got rounded off, the rails got really knifey, and the profile contours got more profound, etc. But if you look at Liddle’s site, he seems to be going more toward accessibility of the experience.

If you look back through Sways, there’s a purple hull I think either Keith M or Lee V shaped and got advice from one of the hull masters about for less than perfect conditions and the thing is pretty flat except in front of the fin.

I think very mild belly or flat bottom blended up into a semi-neutral not-too-thick rail combined with a forward mounted flex fin and the right sweet spot, correct outline and foiling, glassing, etc would get me as close as I’m going to get to classic hull point surfing around here. I’ve had some good long wall rides on the day around here, but it ain’t regular this past year.

babble babble I love hulls and pseudo hulls and quasi hulls



That LeeV cranberry item is one of the inspirations for my current quest! The pic in the TSJ article of Andrini shaping just answered my incoherent question I think. Make the rail line, map out the flats, then blend the rail line to the flat and the slope/degree of the bottom curve will sort itself out.

Moderate hull depth and slightly fatter than pinched rail I"m thinking (like around 1 inch to 1.25 inches at wp at outline cut out before rounding at the end).

Now just got to figure out the overall size. Hoping for input on other thread. Or here…I’m smaller than the average and have small feet. Never really had a board as round underneath as these. Wondering about width needed for glide vs body weight vs size of feet for leverage vs required riding style to make one of these work.

Gothic Dolphin youtube footage maybe that’s just how hulls look when you are watching but board to me looked slightly cumbersome, like a little shy on rocker and slightly too parallel??? Am I cracked?


It’s not the very best footage I ever saw of the actual surfing, but I do think they could almost work in an art museum, and that’s something about the hull undercurrent I really like too–check the favorite surf movies thread for my link to the allaboutsurf article with 8 stubbies clips that are all super good. If I feel like watching surfing, those are what I watch. I think the guy—David Lloyd–if anyone knows him–LeeV, Matt—he should make a full-length surf flick about hulls! Crazy cool music too.

These clips (by the way, I think most of the boards could use a slightly flatter bottom) make me wish for a return to that aesthetic in some bigger way–maybe the flatter bottom numbers being shaped now will bring it back. I just think this style is the shit. Also the Michael Peterson clip from MOTE–I downloaded it from Google video right before it was pulled off the net–need to watch it again–is I think a stepdeck flatbottom stubby (I wonder if I’m just seeing a bump in the outline toward the tail that he’s working off of…) shows the potential in bigger stuff and tons of style

I would think 6 feet and 20 or so ought to do it for you. You didn’t say if you wanted to go as short as possible, but I think if you keep the wheelbase shorter, you’ll be able to turn the width. I wouldn’t go real bellied, but I’m 200 or so too. I wish I could get away with you could. PM me if you get going. It’ll be more impetus for me. I really want to do one of these smooth lined stepdeck flex magic carpets now. In stringerless EPS.

I think the Andreini pic shows him concentrating on the rails first and foremost, not necessarily mapping the flat, and blending from the rails into the round into the flat. I’m gonna be more inclined toward the flat and blend in the reverse order though, with the bottom/rail blend having less roundness overall. Have to–as mushy as it is, this place needs more plane.

Soft enough that I’ll be able to do what I wnat though. My LB trims and turns up and down the face great from the front 1/3rd, where it flattens out, and the rail holds in up there too. Without 6 feet of tail and LB fin holding in at the rear, who knows.


The Andreini pic shows via shadows the overall bottom contour w/ flat in the middle was what I was referring to. My confusing query was about how to fit it all in and a bit about how much flat vs roundness.

I have seen, just now again in fact, those clips on allaboutsurf. Difference between those and the Dolphin surfing is exactly the thing. I think it may have to do w/ relationship between how much roll/roundness is on bottom vs how much rocker; you need plenty curve in one or the other or the board rides more like a pancake. Or maybe it’s about width and parallelness vs bottom roundness. Maybe outline/planshape an issue too if you get too parallel. At any rate, my design ignorance aside, ya gotta have enough curves in the right places to make the board fit nicely into the curves of the wave and curves of your turns. I’d love to see a whole movie of hot hull surfing by all the unusual suspects, w/ mellow music to back it and a bit of historical and design commentary. Fun for us and educate the masses, if they would watch it.

Mentioned in the TSJ article that they shot miles of film and analyzed it frame by frame. Wouldn’t that make a nice shaping room notebook of tips and roadmaps about where others have already gone.

Dave has reels of black and white 8 mm that are better than the versions in 6 Feet to Fit, as I recall. Jeeze over 35 years ago so maybe my recall might be hazy. There did always seem to be a lot of smoke in the room when we watched…

As for the flats and curves…too much curve means too much grab, no glide. Too much flat means not enough grab, no pull. It’s a balance that Greg and the other masters have been dancing for 40+ years. There is definately a flatter area on either side of the stringer. Especially behind the hull on Gregs boards. My raspberry has a pretty round (rail to rail)V. So the flat starts to fade right about the midpoint.

The thing about flats, is that you can use them to increase planing efficiency but you will sacrifice that unquantifiable feeling you get by rolling up on a rail and drifting up to a highline drive…

Alex’s board was a scaled up duplicate of Velo so there was pretty much no rocker. Greg did some of those and worked back up to the 7’-8’ with a rocker that gives trim, glide and drive.

Greg is a pretty light guy (150-) and Steve is no giant either and they were riding boards in excess of 22 inches wide. 21-21.5 should work fine.

Not trying to discourage you from mowing one but I would recommend that you get a Liddle or Andrieni (or others) and surf it for a while, check out the way the curves come together so you have a baseline to work from. Its gonna be really tough to turn out a good one from words and pictures.

I’m not sure if I can address the original question or subject of this thread or not but if it helps… my perspective is there are 3 basic parts to a hull.

  1. Bottom curve.
  2. Deck line.
  3. Rail apex line.

Those three are the basis for the foil of a hull. And the better they are integrated with one another the better over all performance will result.

Change the outline, change your rail shape, like round egg or pointed egg, knife or ?? And, to some degree change how you roll the bottom from rail to rail. OK, but make sure you’ve got your bottom, deck and rail line working together. Probably the trickiest aspect is getting the highest place in the S’d deck below or aft of center and the thickest area of the foil above center.

Take the basic parts, add outline, roll and rails, mix together with cutting tools and sand paper to a fine foiled finish.

BTW you can pretty much see the 3 integrated in the profile view of the link to LeeVs purple board. Again…nice one Lee!



Probably the trickiest aspect is getting the highest place in the S’d deck below or aft of center and the thickest area of the foil above center.

This sounds tricky, like magic–are there any pics of this in profile anywhere? What’s the deck apex do below or aft of center versus further up, even with the thickest area of foil for example?

EDIT: I’m reading this and realizing it could be read wrong–I didn’t mean to be a smart ass–I meant to emphasize HOW difficult that bit of contouring sounds to me!


(sliding off-topic)

Have you seen the Michael Peterson parts of Morning of the Earth? I have downloaded the part from Glass Love I think it is where they’re reproduced. Interesting board. PM me?



LeeV, any further ride report about your berry smoothie?