I am new to Swaylocks and I am trying to find more information on what exactly a displacement hull is and how it works, maybe with pictures/diagrams to illustrate the concepts. Can anyone please point me in the right direction? I have searhed in the forum and on the net, but I am struggling to find what I am looking for! Thanks and regards!
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Thanks for that! I had had a look at this website before I posted but didnât find what I was after on there. It talks about history and evolution but does not help me with the visualization of how it actually looks and works (especially since I have never seen one âin the fleshâ). I am hoping to find something with various angles with descriptions? I am not a shaper, just a very avid and long-time surfer (albeit landlocked at the moment andf surfing the net all the time!)
âŚto see picts and see what other hull riders are saying, go to the âpost your hull second threadâ or like that
OK, I have been onto âpost your hull second threadâ and Iâm trowling my way through it - very interesting pics and great examples of craftsmanship, but still looking for some explanation as to what makes these boards as magic as people say. What I got so far is:
- S-deck - didn't make sense until I saw it on some of the pics - very thin in the tail, then quite a bit of volume, then thinner again, and then the kick of the nose - hey presto, S-deck (duh) - what is the function of that extra volume just under or in front of the surfer's back foot? More flotation? If it wasn't for this bit of extra foam it seems that it would have a pretty normal deck, just with a very thin, almost gunnish tail?
- the bottoms look pretty flat and wide. Are concaves used in the tail (couldn't see yet)
- the rails look like those on an old Whitmore I have back home from the early to mid 60s - very "blady" - is that for the board/hull to penetrate the wave face?
- the bottom deck also seems rounded like on an old longboard.
- the boards look very much like mini-mal funboards in shape. Is this the best shape to use with a hull?
âThe boards look very much like mini-mal funboards in shapeâ.
I read that and nearly sprayed my coffee I was drinking over my laptop.
The Hullophiles are no doubt gathering a lynching party for you.
To all Hullophiles, no offense was meant by my "mini-mal " comment! What I meant was if you placed the board down on its tail, deck facing forward and you looked at the outline of the board. You have to admit that doesnât exactly look like a âmodernâ Brewer derived outline. The boards are wider and have got rounder noses (mind the coffee) and seem almost âold-schoolâ. I understand that this type of design became overshadowed by the Brewer inspired shapes with down-rails that were designed in Hawaii in terms of popularity, and how these are two different ways/styles of riding waves.
Is there animosity or resentment from âhullâ supporters about this? Or are they just happy and glad to be part of a minority group of enwisened wave riders who know that they have got it right and all the other guys on mainstream boards are grappling around in the dark?
Thanks for all the responses so far! Swaylocks rules!!!
(Ps: Iâm stoked I donât have your laptopâs demise on my conscience - hehe).
There is no animosityâŚonly a joke. The outlines are refined versions of Australian short boards brought here in the late 60âs. The bottoms are refined versions of mid 60âs long boards and late 60âs v-bottoms and Greenoughâs flex kneeboards from the 60âs. Refined over 45 years into something that is now quite unique. All of the elements are used to provide the rider with a board that trims well and makes long radius turns using the rail as much as the fin. But most importantly, the design gives the rider a feel that just doesnât happen on other boards. And thatâs why most hullers keep coming back.
There are better pictures of S-decks and rails in the old âshow me your hullsâ thread. Not sure if all the photos are still there. The big problem is that you really canât get a feel for the whole deal without seeing one in person. All the elements are blended so well, the design seems quite simple. But if you have one in front of you and you study it very closely, youâll see how complex the board really is.
Oh, on the classic âhullâ there are no concavesâŚbut fortunately, you can get versions of them with concaves and decide for yourself whether that adds or detracts from the design.
No worries, my wife is always telling me that I take life too seriously, to which I should answer: âIâm just not surfing enough!â
I am starting to get it now, but I agree that I wonât really get it until I have seen one and tried to ride it.
I sent an e-mail to Liddle Surfboards and got some info back from there too.
I am in the UK at the moment and here a hull goes for ÂŁ500. I think the Liddle ones or something similar from the States would be around that or more if you factor in freight.
I have stood in the shaping bay with my shaper before and we have taken a shape he did for me and come up with something completely new - 3 different rail templates for one board. He is quite open minded (which means you sometimes donât get the board youâve ordered!) but then I have also had some amazing boards off him. (Heard this one: if you are too open-minded your brain will fall out)
I will speak to him and ask him what he knows about hulls. I think I asked him years ago but the response was not encouraging at the time.
I have not shaped a board myself before and so I have to trust my shaper to interpret my ideas and give me the feeling Iâm looking for. I once asked him for a board and gave him a string of dimensions - he just looked at me and said: âYou donât know what you are talking about.â I was not offended but took it as positive criticism and that was when my special boards started coming through from him. He has made my brother some boards he really didnât like - their personalities clash!
I think the hull phenomenon never really took a hold in South Africa and so we have no real concept of it. As I mentioned before there are some aspects of it in a 60s log I have, but in what Iâve seen and surfed you go from logs to sort of shorter v-tailed logs (only seen one) to the single fin pins, etc, etc⌠and today you have just mainstream boards shaped there.
Swaylocks is providing me with the inspiration and ideas and gumption to go back home and buck the trends a bit more and hopefullyfind some even more unique places on the wave faceâŚ
I tell you what, this is one hell of a website!!! I had just looked at it before but never got stuck in - now I donât sit down in front of the computer anymore and get bored - thereâs just so much knowledge here and people are so friendly and above all willing to share - absolutely amazing and uplifting in our medern me, me, me times!
Aloha for now
OK, Iâll stop going on about how amazing this site is (well, Iâll try!)
Mike?
(j/k)
So glad you asked. As a recent recipient of Naval Architecture of Planing Hulls I am now an instant expert in all matters of displacement, even though itâs not mentioned much in the book so far. First of all planing. Planing is when the craft skims over the surface of the water. Displacement is when the craft ploughs itâs way through the water, very much like the hull of a boat. Like it or not, pretty much all surfboards displace water to some extent. If you know of a surfboard that doesnât displace to some extent, please let me know, Iâd very much like to hear from you.
Getting back to displacement on a boat you could imagine how well a hull with a square front, that sits below the waterline would make itâs way through the water. Pretty damn terribly to say the least. Replace the front of the boat with the hull shape you see on most boats (v shape) and the boat will push itâs way through the water much better. Remember not many boats sit on the surface of the water.
Most sit below the waterline, mainly because of the weight bearing down on them. With enough speed however, the right boat (say a speedboat) can plane across the surface of the water, but you need a fair bit of speed and the right hull shape, (not to mention a boat that is light enough) to be able to do this.
Hi Dean -
Absolutely correct⌠surfboards are a combination of displacement and planing hull.
To the rest -
How else might one explain the fact that a board that doesnât float worth a damn when sitting in the lineup suddenly supports oneâs weight when at speed and skimming? Itâs planing and yes, âdisplacement hullâ surfboards do it too.
Witness the portion of the board still below the waterline? Thatâs actual displacement and all boards do that as well.
I know there is safety in numbers and having the same kind of board as all your friends but to drink the kool-aid and proclaim a certain type of board to be one or the other is a demonstration of lack of understanding or a refusal to adopt accepted terminology. For those still locked in their little world of what is and isnât, read that book to which Dean refers.
Surfboards are all about personal preference and different strokes. Fact is, there are lots of boards that work and on any given day, any one of them might be âmagicâ to the right rider.
Thereâs some damn good marketers out thereâŚ
Thanks for all the feedback!
I ride the boards I ride as before I didnât know any better.
In South Africa I have never heard mention of a displacement hull, let alone ever seen one or ridden one. I think our surfers and shapers/designers just ran with what was popular. This doesnât mean that there are no hulls in SA, just donât know of any.
I have always ridden ANY board I could lay my hands on, big or small, fat or thin. I donât care much for what my surfing looks like, what interests me is what it feels like and through this to where it transcends me. I donât care much for organised religious activities, I find my spiritual sustenance in the water on a wave, reconnecting with the primordal ooze from which we collectively crawled out of just over 500 million years ago (give or take a few million years, with dating being the science it is).
Out of all my surfing friends from over the years, one of them has taken to surfing fishes, but still balks at the idea of riding longboards in summer, even though he lives and surfs in Wales, UK! I donât know of any that ride a log with any regularity, itâs just not cool! Most of them will probably start moving on to âbig boy boardsâ soon or maybe the odd mini-mal or mal, but that will probably be it. I do not think that they are in search of newer surfing experiences that are âmoreâ or deeper, rather, they want to hang on to what was, the way they used to be able to surf when they were younger and more physically able.
I had pretty much made my mind up about hulls when I read about them the first time in a journal or path a few years ago, but as I get to surf much less than I would like to (should!) it has been a very gradual process. I like the saying that good things come to those that wait, especially when applied to surfing. You can paddle out with the intention of catching loads of waves and ripping it up and psyche up with some heavy metal tunes or punk or whatever gets you super amped, and you could then paddle out and rip it up, but more often than not you will just end up frustrated and having pâŚd the rest of the crowd off too. OR, you look at the ocean, time the sets, look at the way the waves are breaking, do some mind-surfing, listen to some chilled tunes, paddle out, find a spot and wait for the waves to come your way, as they will invariably do. You glide, not scramble, into the waves, and instinctively pick a line, maybe fitting in the odd turn, definitely looking to be in the hollowest part of the wave at exactly the right time and trimming on the right line and then pull out with a smile on your face, grinning to the core of your being (like the cartoon on âSproutâ where he ends up drawing fart face). In this way riding a wave, picking a pleasing line through a tricky and challenging situation becomes a metaphor for lifeâŚ
Different boards spring from different attitudes and lead to different experiences⌠I feel Iâm ready for the next step⌠to hull or not to hull, that was the questionâŚ
My options at the moment are to get a hull here in the UK or from one of the originals or find out what I can, speak to my shaper back home and see what he comes up with. The last option makes the most financial sense as I have to be able to justify to myself and wife and family how much I spend on surfing equipment, but then again he is a traditionalist, albeit open to new ideas and experimentation. Last time I saw him his favourite board was a Joel Tudor 6â6", which looked weird at the time but makes more sense now and could have been a bit of a hull? Problem is I end up picking up the tab for whatever he comes up with. I think that getting a UK shaped board or eg. Liddle will probably come down to about the same cost and at least double that of a South African board.
Common sense tells me that I should get a board from the person with the most experience, so at the moment I am thinking of getting a Liddle.
Any advice? How difficult is it to shape a hull?
Enough ruminations for nowâŚ
Actually, one more thing - I have got lots of info and am much more clued up now (I understand the difference between planing and displacement hulls), but still wondering how each individual element of the design works/what it does and how they all combine together to make for a magic carpet ride? Most intriguing for me is the extra volume in the tail that causes the S-deck to form.
PS: I am looking out for âNaval Architecture of Planing Hullsâ, saw one on Amazon, heavy price tag, will keep looking
PM sent to you hansman
This is one of the first cut down longboard designs that John Bradbury did. It fits your explanation well. Everything but the fin is in original condition. JB, being featured at the Sacred Craft shape off this year in Ventura, was onto the progression early on. This one was pulled out of the back of somebodyâs car and given to a friend as a gift for passing on the stoke and knowledge.
Anyway, itâs been posted before and here it is again. Early Creative Freedom Lam.
http://www.surfboardshow.com/shape-off.html
First off, John Mellor is correct as usual, a name is only a name; hulls plane and displace water, flat bottom boards plane and displace water. Consider the name âhullâ to represent a certain kind of surboard design just like âfishâ represents a certain surfboard design. Deal with it 
You really canât divvie up the different design elements on a hull like you can on other boards because they only work together. Take away the pinched rail; the board wonât rail turn, take away the s-deck; the board wonât trim and the tail wonât flex, take away the flex fin; the board wonât rail turn and drive. Its all of those elements together that create that unique feel. The whole is greater than the sum of itâs partsâŚ
Iâm not sure what you mean about the added volume to the tail. Most hulls in the 7â range have really thin bladed tails. The volume is the minimum required to install the fin box. The s-deck, in my mind, is a way to keep as much float (foam) as possible in places where it does the most good. The tail is thin for flex, the nose is thin to reduce swing weight and accomodate the rail rocker. Where else can you store the foamâŚright in the middle. Greg Liddleâs version has more foam than others because the design was intended to work in very small surf. In better conditions, you can get away with a bit less.
The distribution of foam is carefully designed not just for float. Trim is a huge part of the hull experience. Basically, the turning sweetspot is the same place as the trim sweetspot. That is achieved by moving the foam around (foiling) so the board balances with the rider in the exact place where the rocker and bottom contour work best for turning. You can adjust the foil and hull location fore and aft to make the board surf differently for different surfers and conditions without losing the basic appeal of the design.
The outline can also be used to adjust the sweetspot but more , it is used to design drive and turning radius. The more foreward the wide spot; the more drive and long the turning radius. The further aft; the shorter the turning radius.
If this all sounds like religious raving, one could go on the same way about thrusters and fish or neuevo olos. The hull isnât for everyone. Hell, I even go through a WTF stage when I jump back on mine after riding fish or thrusters. But once I get my hull legs back, the magic happens.
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So glad you asked. In my experience a surfboard can be broken down into several âpartsâ listed as follows.
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Outline
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Rocker
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Bottom contours
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Rails
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Foil (distribution of thickness throughout the object)
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Fins
For todays lesson boys and girls Iâm going to cover my theory on outlines. If you compare a shortboard to a longboard, what really distinguishes the two (in my view) is the outline. Theyâre completely different! Now what does this have to do with displacement (and planing) you might ask?
Well if you increase the width of the craft you are riding you increase the leading edge and henceforth increase the planing area or so I have read. Ask anyone who rides a fish and a shortboard regularly and they will probably tell you that a fish has no shortage of planing area. No prizes for guessing why.
Also remember that when you are surfing you are traveling more sideways than forward. Itâs the wave thatâs moving forward towards the beach, youâre just along for the ride. What has this got to do with outlines? In my theory, quite a bit.
Iâll supply a couple of diagrams later on today to clarify, but I feel the way a shortboard outline greets the oncoming water (when you are trying to build some speed) can be quite blunt. Fishes, not quite so. Longboards, even less so again unless I am very much mistaken. Iâll explain why I feel this is so when Iâve had some breakfast and done some other things this morning!