Surfboard Science For Dummies: Quads 101

A few years ago, Hawaiian pro surfer Mikala Jones turned me onto the joys of riding a quad (four finned surfboard). Just like a girl, at first I could see no wrong and we made love all the time. It was awesome.

A quad (4 fins) setup.

A Glenn Pang shaped T&C quad (4 fins) setup.

Then something changed.

I remember the moment vividly: It was a solid six-foot set at Blacks that I'd been waiting for all day and I was right in the spot, perhaps a little late, but I'd pulled later drops than that. Just as I'm standing up and anticipating getting shacked out of my gourd (football analysts call that "running with the ball before you catch it" and it’s something you shouldn’t do), something went completely wrong. In an instant, I'd gone from wave-of-the-day status to look-at-the-kook-getting-pitched.

I couldn't figure out what went wrong until I got to talking to Quiksilver In Memory Of Eddie Aikau invitee Mark Healey, who had the same thing happen to him—on a 25-foot wave at Waimea Bay. "Yeah, quads kinda tend to slide out on late drops," he said in between shark stories. It all made sense after that and I've since re-evaluated when and where to ride my quad. To help break down the nuances of one of surfing's hottest trends, I asked renowned Australian pro surfer/shaper Dylan Longbottom and Town & Country shaper Glenn Pang a few questions…

TransWorld SURF: Why are quads so fast compared to a thruster?

Dylan Longbottom (left) with team rider Laurie Towner. Photo: Justin

Dylan Longbottom (left) with team rider Laurie Towner. Photo: Justin

Dylan Longbottom: I find they are faster because they don't create as much drag as a thruster because there's no center fin. With a quad, the water just flushes out the back of the board, as there is a lot more area there in between the rear fins allowing it go faster.

Glenn Pang: Quads go faster because the center fins give a lot more drag than the two side fins, you would think that with more fins you would have more drag, not so.

Can you explain why quads have such a tight turning radius and are so loose?

Dylan: The back fin on a thruster is set around 3.25 inches from tail making it a lot more controllable but a little tighter—that's why you can surf a lot more top to bottom where as the quad will want to do more of an arc off the top. The back fins on a quad are around 5.25 inches from the tail, which is a big difference, compared to the thruster. That difference alone gives quads a more free-flowing feel and makes them looser.

Town & Country shaper Glenn Pang.

Town And Country shaper Glenn Pang

Why did I eat shit so hard dropping in late on a quad the other day? Do quads not dig into the face as much a thruster?

Dylan: This is a good topic. When I surf Shipsterns Bluff I ride a thruster because after you airdrop the step, the back fin will grab and hold a line where as my quad will tend to skim across the surface more and that extra second makes the world of difference on a late drop. I think it comes down to the way a thruster drives, you need to hold a solid line whenever taking a late drop. A quad is more likely to slip and slide into a late drop. Quads are much better once in the barrel though, as you got your two side fins in the wave face holding you in. And when the foam ball knocks on the tail of your board, you can definitely feel the lift and are able to ride it out. On a thruster it's a lot easier to get bucked off in the barrel.

Glenn: On a thruster, the third fin acts as an anchor, it helps hold the tail in. That’s why you probably ate shit on the late drop, there was nothing giving you support on the tail to help hold you in.

Dylan puts his quad to good use at an Aussie slab. Photo: Jones

Dylan puts his quad to good use at an Aussie slab. Photo: Jones

What's the knock on quads backside? Is it just me, or do they work better frontside?

Dylan: I think you tend to draw different lines on your forehand and definitely vary your moves a lot more making the quad very creative to surf whereas on your backhand, most people surf top-to-bottom which suits the thruster a lot better.

Glenn: Quads can also be made to ride closer to thrusters depending on the fin placement. The closer you set the rear fins to the center of the board, the more positive the board will feel. Example, on my quads made for larger waves, I set the rear fins 1 3/4″ in from the rail as compared to ones made for smaller waves, which are set 1 5/8″ in from the rail. Also, on the bigger boards, the tails are usually a lot narrower, which make the rear fins even closer to the center of the board.

So there ya go. Find yourself somewhere with an easy takeoff followed up by a long, draining barrel, and if you're armed with a quad, chances are you could be in for the ride of your life! To check out some of Dylan Longbottom's handiwork (I've had several magic boards from him) go to

Dylan Longbottom puts his equipment to use at P-Pass in the Caroline Islands.