Talking Design with Rusty: The Secret Behind Displacement and Big-Guy Shortboards

Hayes Domler Asks:
"I've been surfing for over 30 years and have gone from shortboards to longboards and back to shorter boards. I'm 6'0, 200lbs. I'd love to get a big thruster that would work in quality surf and would probably work in average surf, too. Can you help me?"

Rusty, being a big guy himself, tackles the question head on:

What's considered big for the non-surfing man? Let's say 200 pounds and up. So what's average for a surfer? Well, for argument's sake, let's say 150 to 170 pounds. But 180 is starting to tip the scale. Any pro surfer 190lbs is considered big -- Jordy Smith, Jay Davies, Pancho Sullivan, Sunny Garcia, Luke Egan -- while 200lbs is considered really big. Simon Anderson, a.k.a. The Gentle Giant, surfed in competitions at 6'3" and 210 pounds. There are a lot of very fit surfers who are, simply put, bigger than average.

simon1 Thruster-inventor and former World #3 Simon Anderson was a big dude, which never slowed him down, especially at Sunset. Photo: Dan Merkel/A-Frame

At 200 pounds, a young, fit guy surfing in good waves can probably make 6'2"x18.5"x2.3" work for him. Yet, 6'3"x18.75"x2.4" is probably a little more practical.

Here are some other examples. A retired pro surfer in his mid 30s, standing at 6'3" and 230 pounds would probably ride a 6'5"x19.5"x 2.5". But when he was in competitive form, he probably would've weighed 200 pounds and rode a 6'3"x18.65"x 2.3".

Or take a 6'5", 230-pound, professional athlete in his early 20s who is an experienced surfer. His board would be 6'6" 19.75 by 2.6. Meanwhile, a 6'7" 230-pound retired NBA player in his early 40s would need a 6'10" 21 by 2.8-inch board as an experienced surfer.

Then factor in age, fitness level and venue, and the numbers change.

A lot of guys fall into the "vanity versus reality" funk -- if you're working too hard and not enjoying yourself on the same board or dimensions that served you well a few years ago, go a little bigger. If fun becomes work, you're only hindering yourself. Go a little longer, wider, thicker and you will increase your wave count and stoke. You'll probably surf more often and the fun and fitness will be restored.

People often ask whether there's a formula for volume. Here's an astute observation from one of the readers of our previous blog:

Tom G. 05/19/2009 04:25 PM
"Could you help bring back the volume measurements of surfboards? Maybe even weigh the boards too...(~5-10% difference). It could improve consumer confidence (for the average guy) in avoiding the worst purchase for most surfers -- a sinker that floats you at your neck! For example, some people think you should surf something no less than 35% of your volume. So if I weigh 77 kilos (170 lbs) I should surf a board that displaces 27 kilos of water (27 liters). Would this help the movement?"

Jamie O'Brien weighs in at about 180 pounds and typically his go-to board is 6'2"x18.5"x2.27" inches and displaces a volume of approximately 27.5 liters (or about 77 beers, as one CAD program conveniently calculates.) I've made him shorter, wider boards and I do use the volume tool on the software as a cross check.

Jamie O'Brien putting his edge to the test at Teahupoo. Photo: Sean Collins

Nate Yeomans weighs about 170 pounds, though he rides similar dimensions with slightly leaner rails. So I would say you are on the right track, Tom.

Ability level and venue also must be taken into consideration, and in no way is it meant to be disrespectful, but these are realistic factors when finding the right board for you.

Alex from Sweden 05/20/2009 02:43 AM
"I'm 6'3" and about 220 pounds with wintersuit and all. Even worse is that I surf mostly in the Baltic Sea that is cold and has much less salt, meaning less buoyancy. I don't fancy longboards or funshapes because I want a stable board that can carve and snap but still handle less buoyant water. My question -- what kind of board, and especially size, do you think would suit me?"

Venue is always a factor. Again, another spot-on comment, this one about salinity and buoyancy. The best way to add volume is to add width. This will increase stability but the trade-off is a reduction in reaction time. Wide boards aren't necessarily any slower than narrower boards in terms of how fast they are capable of traveling down the line but width directly affects the quickness of a board with regards to rail-to-rail transition.

Simply put, for bigger surfers: width is your friend. You don't have the same quick twitch muscle speed as your smaller brethren. You have more power. Design you board accordingly. Head high is all relative. Adding thickness will add buoyancy -- the trade off is a decrease in flex and sensitivity. And while adding length may allow you to catch the wave a little earlier, the trade off is possibly compromising how the board fits in the curve of the wave and increased arc length on turns.

A big part of a shaper's job is finding a good balance between all these variables.

Your board should somewhat reflect your build. Shorter, stockier surfers should probably consider adding the extra volume they need with a little extra thickness. Taller, leaner surfers may be better served by going a little longer, and wider. The extra width is important to maintain outline curve. For every two inches of change in length (+/-) approximately an eighth of an inch (+/-) will keep the curve somewhat similar.

Foot size also comes into play. Sasquatch doesn't want his toes hanging over the rails and he can probably handle more width because of the leverage he can deliver with his big feet.

Pancho Sullivan - big guy board, big-guy carve. Photo: Jeremiah Klein

It's difficult to generalize and that's why I think it's so important for anyone who wants to maximize his or her surfing to work with an experienced shaper on customized equipment. Once again, this isn't so much about old-guy or fat-guy boards, but really trying to throw out some practical solutions for the surfer who's bigger than average and frustrated with trying to find a happy middle ground between challenge and reward.Average sized surfers are generally happy with fins that have a base and height of around 4.5 inches and a flex pattern that incorporates a somewhat softer tip. Bigger surfers should be looking at fins in the 4.65 to 4.75 range, base and height. Also, avoid softer fins. Plastics are a no-no. Some RTM fins are good. Carbon tends to be too rigid. Nothing beats a well-foiled, all-fiberglass fin. In smaller surf you can sub in a set of five-inch (give or take 1/8") front fins for more lift and drive and drop in a smaller rear fin to free up your tail.

Quads? I'm a big advocate, especially for larger surfers in everyday conditions.

As far as materials and construction go, bigger guys have more to gain from EPS/Epoxy. With lighter, quicker surfers, I usually adjust the volume down to compensate for the increased buoyancy. While bigger or more "experienced" (a.k.a. older) surfers usually choose to enjoy the additional paddle power.

There are so many variables to factor in, but here's a stab at a super basic spreadsheet:

#1: A board with typical shortboard proportions. (From a distance, under a bigger surfer's arm or on a wave, it would be difficult to tell how long the board really is.)

A 3-inch difference between nose and tail
Nose 11 to 12 inches
Tail 14 to 15 inches
Wide-point an inch or two back
More of a "back foot" design

Assuming average ability, average surf condition and that the surfer is reasonably fit, surfing three-plus times a week.

20 to 30 years old:
200lbs 6'6" 19.5 by 2.5
225lbs 6'9" 20.0 by 2.65
250lbs 7'0" 20.5 by 2.85

30 to 40:
200lbs 6'9" 20.25 by 2.7
225lbs 7'0" 20.75 by 2.85
250lbs 7'3" 21.25 by 3.0

40 to 50:
200lbs 7'0" 20.5 by 2.75
225lbs 7'3" 21.0 by 2.9
250lbs 7'6" 21.5 by 3.0+

50 to 60:
200lbs 7'3" 21.25 by 2.9
225lbs 7'6" 21.75 by 3.0
250lbs 7'9" 22.0 by 3.15+

#2: A little more balanced, user-friendly shape

A 1.5-inch difference between nose and tail
Nose 13 to 14 inches
Tail 14.5 to 15.5 inches
Wide point moves closer to center

Assuming average ability, average surf and a reasonably fit guy, surfing one to two times a week.

20 to 30 years old:
200lbs 6'6" 20.5 by 2.65
225lbs 6'9" 21.0 by 2.8
250lbs 7'0" 21.5 by 3.0

30 to 40:
200lbs 6'9" 21.25 by 2.75
225lbs 7'0" 21.75 by 3.0
250lbs 7'3" 22.25 by 3.1

40 to 50:
200lbs 7'0" 21.5 by 2.85
225lbs 7'3" 22.0 by 3.0
250lbs 7'6" 22.5 by 3.15+

50 to 60:
200lbs 7'3" 22.25 by 3.0
225lbs 7'6" 22.75 by 3.125
250lbs 7'9" 23.0 by 3.25+

There are many other options in design that will allow you to go shorter if you choose. Boards that are wider in the nose and tail with more relaxed rockers work for certain types of waves. Or go longer for that matter. It's all about the waves you surf and the lines you want to draw.

Form follows fun.

Check out Rusty's Blog on and Keep Those Questions Coming!

2 Responses to “Talking Design with Rusty: The Secret Behind Displacement and Big-Guy Shortboards”

  • Jay S. June 30, 2009

    Ok, so I am 56. Weight 175#. Am in pretty decent shape. I live on the Texas Gulf Coast, so I surf a lot of waist to chest high junky surf. I do get to travel some, and want to go smaller, but I like catching a lot of waves. What size do you suggest? Thanks. Stuckey

  • Mac March 17, 2011

    Jay, after reading this article, I would recommend you a 7'6", 21.5", 2.75". What do you ride now?