hull bottom questions

Aloha hull bottom fans

I was recently turned on to the displacement hull design via the Andreini Vaquero model, and was fortunate to ride my 6’10" in multiple sessions at Jeffrey’s Bay this summer. I found the speed and trim and slingshot effect off the bottom to be intoxicating, and I would like to expand my hull bottom experience.

Checked out the liddle website and am wondering if anyone out there has any experience on his (or similar) 2 plus 1 hull bottom designs. Specifically, does this fin configuration reduce the sensations endemic to hull bottom designs, or does it open up more waveriding possibilities for hull enthusiasts?

I live north of Santa Cruz and spend the majority of my ocean time in heavy beachbreak conditions. We do get some amazing days when a hull bottom would figure 8 all over the place (I think) but my pointbreak surf sessions are limited.

Any recommendations on designs that will give the hull bottom experience in a variety of ocean conditions (beach, reef breaks)? I am afraid the 2 plus 1 will ride less like a single fin displacement hull than what I am after.

Thanks for your help, happy surfing


Hello Kit,

The term ‘Displacement hull’ is used to describe a hull which is designed to be efficient at displacement (non planing) speeds, which for a six foot board will be about 2.5 knots. I presume that the board you are using is actually a planing hull, and is inaccurately described as a ‘displacement hull’ by the manufacturer. Do you have any pictures of the board?


PS Efficient displacement hulls are very narrow in relation to their length, and achieve higher displacement speeds as they become narrower. A rule of thumb for an average hull (which is easily exceeded by an efficient narrow hull) is that the maximum displacement speed will be approximately equal (in knots) to the square root of the waterline length (in feet)

Kit, you are not too far from Plaskeet Creek in Big Sur. Come to the Sept. 17-20 Swaylocks get together and see some fine hulls. If Matt and the “pool guy” are coming and bring the sticks they brought last year, you would be in Hull Heaven. They have a bunch of Liddles, many by Paul Gross(I am bringing 5 PG’s) and I think they have some Andreini’s as well. Most, if not all of these boards are available to test drive…


Kit -

I’ll bring an older 7’10" Liddle that is a bit thicker than some. It is a single fin but you are welcome to try it out.

I have heard Mccoy’s loaded dome discribed as a displacement hull, but from what I have seen called a displacement they don’t look the same.

Mccoys run from tip to tip and rail to rail. Is this what you guys are talking about when you say displacement hull? Or something else.

Hey Kit , I work with Liddle and Andreini and the 2 plus 1 set up do not hurt the feeling of the hull at all. Surfing up north that set up would come in handy a lot.Glad you got your Vaquero in some good surf.Try and make it to Big Sur I will have a full load of displacment hulls to share.

Solo ,ask any body who knows me and they will tell you I have big mouth and love to talk surfboards. But I cant type for beans . A must read on Hulls is the Surfers Journel vol.3 #1 Greenough the ageless artist by Paul Gross. And if you have it or can get it Longboard Quarterly vol. 1 # 2 Midlencths the fuctional underground. Also the Simmons story in that same journel is kinda where Dissplacment Hulls started.


I get the same label myself. Thanks for the info. I really like the loaded dome from Mccoy and I am wondering if it’s a displacement type hull. I realize each shaper puts their own touch on these things.

Hey Solo what area are you in , Spencer Kellog is doing some nice Nugget type hulls, just did a nice 5 fin bonzer I saw . He shapes out of the Ventura surfshop.His boards have a bit more hull than the McCoys Ive seen, they seem to have a more subtle curve on the bottom.

i plan on bringing a few, “sons of simmons” midlength hulls to SA 2004…

Er. . please excuse me if I am being annoying, but I find it hard to imagine that any of the boards you are describing are ‘displacement hulls’ . Is ‘displacement hull’ being used as a marketing term? It is certainly a misnomer when applied to a Mc Coy shortboard. Every board is a hull, but displacement hulls are hulls which are designed to be efficient at non planing speeds. As this is a design forum it is confusing to use formal nautical design language in a way which is misleading.


I have spoken to Spencer. I think he has also had some dialog with Geoff. I will ask Geoff what the difference is.

One thing is for sure; The boards spencer is doing are nothing like the bottoms Geoff is putting on his nuggets. I don’t think someone can just copy something that has 45 years behind it. From what I hear about the dome it’s not an easy bottom to put on a board. It is very subtle.

I am interested in other like designs and would love to see some of the others. Many shapers that have been at it for awhile come up with their own things and figure out how to make them work. That the beauty of handshaped customs.


Er. . please excuse me if I am being annoying, (OK your excused) Every board is a hull, but displacement hulls are hulls which are designed to be efficient at non planing speeds.

Like riding a surfboard.

Hey Roy , could you go to and go to origins that should tell you the story of why that term is used.thanks KP.

Surfboards are designed to be efficient at planing speeds, displacement hulls are designed for non planing efficiency.

Hello Kirk,

Thanks for the link to Liddle surfboards, I haven’t seen that kind of full rail bottom turn for a while. I think I see why the term ‘displacement hull’ is being used ( longer, narrower boards, using more rail and with more bottom roll?) Strictly speaking they are still planing hulls, not displacement hulls, but I’m not going to argue over terms, now that I know what you mean by ‘displacement hull’ there is no confusion. The boards look very nice.

Regards, Roy


Bring Rocket 88, I wanna get a template off it, OK…???..

Paul (aka: Yankee Doodle)

No problem mi amigo .

how do you spell displacement backwards?..sdrawkcab tnemecalpsib…good job roy that was down right civil and thoughtful and you didnt rock the old guard unnecessarily…{ jimmy said some call it the Liddle league } wait till I finish my J-boat clipper planing catamaran.hydro foil pintail reverse chine ballast skow…then we will see if you can with stand the terminology tourture olympix conundrum…ambrose …always wear a conundrum when surfing in post flash flood runoff from urban academic areas

Ambrose you crack me up.Liddle says you guys are in for a early opener on mon. or tue. Grab your paddle and glide.Aloha KP