If you’re given to trawling board racks in surf shops or following shapers on social media you don’t need me to tell you that twinnies are back in a big way. It’s not a resurgence but a re-resurgence. We’ve been here before, a few times in fact.

This particular twinny renaissance marks itself by an improv approach to two fins; a cross-pollination of old twin fin designs that’s creating multiple hybrids. Yet twin fins have a long history, one that dates back to Tom Blake, and the design has been used to achieve a variety of outcomes from dead ahead speed runs to turn-on-a-coin agility.

Following is a potted history of twin fins covering all the categories to date.

Simmons Dual Fin

In the late 1940s Bob Simmons, a shrewd engineer from Pasadena, got a carpentry job with Gard Chapin, Miki Dora’s volcanic step-father. Simmons wasn’t a surfer, yet upon Chapin’s insistence he began to learn, and he also learnt to build boards after work hours. Simmons chanced upon Naval Architecture of Planing Hulls, a technical manual for boats, and applied the same principles of speed and manoeuvrability to his surfboards.

Simmons cared little for aesthetics, instead building crude yet functional craft. Surfboard design was in its infancy yet it instinctively erred toward the long and the sleek, while in contrast Simmons’ boards were short and squat - approximately 8 feet by 24 inches. He assumed that a broader tail was a key to high speed, yet it also tended to spin out. In 1948 he solved the problem by fixing two crescent-shaped fins to each corner of the tail. The fins were set parallel to each other.

A Simmons Dual Fin on display at Mingei International Museum, San Diego

Ironically considering the attributes of later twin fins, Bob Simmons was never much interested in turning. As Matt Warshaw says in The History of Surfing, “Engineered speed was all that Simmons cared about - the rest was frippery.”

Bob Simmons in full flight on a Dual Fin, way out ahead of the curl at Malibu (Joe Quigg)

In 1954 Bob Simmons was struck in the head by his own board - a Dual Fin - and drowned while surfing Windansea in San Diego. Fifty years after his death an abbreviated version of the Dual Fin - dubbed the Mini Simmons - receives a burst of popularity. The Mini Simmons is first shaped by Joe Bauguess from San Diego and then championed by surf-historian Richard Kenvin, also from San Diego.

From the very beginning, twin fins are inextricably linked to the Southern Californian surf town.

Fish

In 1967, Bob Simmons Dual Fin concept entered the modern era when San Diego brothers Nick and Barry Mirandon of Surfboards La Jolla created the Twin Pin, a longboard with a deep swallow tail and a fin on each ‘pin’. The Twin Pin had minimal popularity, however it’s noted here as it was the design inspiration for the most enduring of all twin fin configs, the fish.

The Twin Pin by Nick and Bear Mirandon of San Diego

San Diego kneeboarder Steve Lis fixed the Twin Pin’s back end to a full nosed kneeboard. In time he’d switch the fins to traditional keels, not dissimilar to the half-moon keels Simmons used, except only foiled on the outside. Lis also also set the keels parallel to each other - again like Simmons.

With the Shortboard Revolution in full swing and stand up surfers casting about for new ideas it wasn’t long before San Diego surfers were riding the sub-six foot fish as a stand up board. The concept was indigenous to San Diego, being well-suited to the hollow reefs around La Jolla, yet it bogged in slower surf and spun out in big waves which limited its popularity elsewhere, at least for the time being.

A Steve Lis-shaped fish (Hydrodynamica)

When the 1972 World Titles were held in San Diego, a group of locals stole event favourite David Nuuhiwa’s fish, broke it, then strung it from the jetty with the words “Good luck David” scrawled across the bottom. It was, after all, ‘their’ design. Fortunately, Nuuhiwa had another fish and he rode that to second place. Hawaiian Jimmy Blears came first - also riding a fish.

Despite the iron-fisted approach of San Diego locals, the fish design slowly spread, though it would take a 1990s revival to truly reach international cut through. In retrospect, the fish is the only design idea that remains intact since the Shortboard Revolution. And though it’s morphed and evolved in the fifty years since Steve Lis unveiled it, the traditional fish design is distinguished from all other twin fins by having three fixed elements: a swallowtail with keel fins that run parallel to the stringer.

Early 70s Twins

In 1970, a number of Australian and US shapers, notably Geoff McCoy, Mike Eaton, and US expat Tom Hoye (who’d later invent Da Claw, a five fin board) craft short, pod-shaped twin fins. Like the Dual Fin, the fins were placed on the rear corners. The boards were similar in shape to paipos - Hawaiian bodyboards - that also had two fins. The theory goes that, just as stand up surfers repurposed the fish kneeboard, so to did they refashion the paipo for their own pursuit.

Unlike fish, the early 70s twins didn’t have keels but ‘tuna fin’ shaped fins, and they also had the fins toed in. Subtle though it is, fin toe was crucial for the designs to come, such as the Thruster. Fin toe increases responsiveness by keeping the board in turn mode, and it was widely adopted in all later multi fin configurations, the traditional fish notwithstanding.

George Greenough weighed in with his observation on the twin fin design: “Twin fins work better the closer together you put the fins till you get a single fin". Unperturbed by the great one’s disdain, the public bought in with twin fins accounting for a reported 50% of the Sydney market in 1970, while an April 1971 issue of Surfer magazine shows 13 ads with twin fins. The same issue a year later has just 2. The reason for their short-lived popularity was an inherent lack of drive and an alarming propensity to spin out. It didn’t help that they arrived on the scene at the nadir of the Shortboard Revolution - when boards were at their very shortest. If the same fin configuration was placed on a 6’6” and not something 12 inches shorter they’d have been more dependable.

Geoff McCoy with a twin fin in 1971

In late 1972, a 15-year-old Mark Richards visited Hawaii for the first time and provided a harbinger of what was to come. MR included a Geoff McCoy twin fin in his quiver. “I surfed my twin fin most of the time I was there,” MR says in a 1973 issue of Surfing World.

Late 70s Twin Fins

For three years during the mid-70s, Reno Abellira included a stubby fish in his quiver for the Australian contest leg, and in 1976 he rode it on a small day of the 2SM Coke Surfabout. MR won the contest but noted Abellira’s performance on the 5’3” x 20” fish: “His fish was skating over sections at speed where others were bogging down.” Having abandoned twin fins a few years earlier, preferring an Aipa Sting as his small wave board, MR revisited the twin fin idea. His first board was the ‘Bumble Bee’, 5’11” long by 22” wide with a bulbous nose inimical to the savagely angled surfboards of the day.

The Bumble Bee worked, but only in waves up to 3’ after which it spun out. Following a shaping stint with Dick Brewer, MR took the Hawaiian master’s advice and applied the twin fin concept to a customised single fin outline. The resulting planshape was similar to a stretched-out fish, with sharper nose and narrower tail, plus the inclusion of flyers to further reduce tail area, while the fins were shifted up the board for maneuverability. It’s the classic twinny set up. The rip, tear, and lacerate arrangement. It's also what most people think of when they refer to twin fins.

Having the pivot point (i.e the inside fin when turning) inside the centre line is the key to twin fin dynamics; the turn is initiated quicker than on a single fin, and the board also can also turn along its outline as well as its rocker line. Also, with more fin area to push off and a wider tail than the single fins of the day, the twinny was significantly faster.

Mark Richards 1977 'Free Ride' board

MR rode his twinny to four straight world titles but the design wasn’t without its critics. “Here's what I remember best about twin-fins,” wrote Matt Warshaw in a Surfer article titled ‘Twin Fins: They Mostly Sucked’. “Yes, MR ripped on 'em. Dane too. And young Martin Potter. The rest of us struggled. God, we struggled. Off the bottom, twins were as reliable as a wet paper bag. Top-turning, you get a little foam between the fins, you might as well be riding a unicycle up there.”

In ‘81 Simon Anderson unveiled the Thruster and by late 1982 - MR’s last world title year - 75% of surfers were riding them. What followed next was fifteen years of three fin fascism, Bruce McKee shaped quads but only Glen Winton noticed, Wil Jobson created the Twinzer - a twin fin with forward canards - which Martin Potter rode for six months, while Skip Frye and other dogged San Diegans slowly, quietly evolved the fish.

The Fish Revival

Several parties can lay claim to the mid-90s fish revival. In 1994 Tom Curren rode 12 foot Bawa in Indonesia on a 5’7” Fireball fish shaped by Tommy Peterson, and the session was published in several magazines plus it was featured in Rip Curl’s original Search video. The name of Peterson's board was somewhat of a misnomer as it had a standard Thruster configuration though it did share the fish planshape. The Australian surfing public was still largely ignorant of what a fish really was, as evidenced by a 1994 article in Tracks ‘What Is a Fish’ that had to spell it out in plain terms.  

Around the same time, Andrew Kidman and Jon Frank were looking sideways at surf culture and trained their lens on Derek Hynd riding a Skip Frye-shaped fish at Jeffreys Bay. The footage was the high water mark of their 1996 film, Litmus.

Down at Ulladulla on the NSW South Coast, Mick Mackie recalled his grommethood where he’d seen older surfers standing up on kneeboards at Cronulla Point - more evidence of equipment repurposing. Mixing kneeboard design with Dimitrije Milovich’s Winterstick - a split tail snowboard - Mackie spun new DNA into the fish design. Sidecuts, flextails, and deep swallows were part of Mackie’s oeuvre - but they were all still fish.

Though he incorporates sidecut and flex, Mick Mackie maintains traditional elements in his fish such as parallel keel fins

Though shapers such as Mackie, Skip Frye, and Dick van Straalen were maintaining design integrity in the fish, during the 90s many others pushed the boundary of what a fish was, crossing it with quad and Thruster set ups, and pushing the classic planshape till it only vaguely resembled Steve Lis' original vision.

The Duo

The most recent original twin fin design is Neal Purchase’s Duo, though it’s an idea that had surfaced before, most notably with Bill Thrailkill in the US. Purchase was unaware of Thrailkill’s boards when he set two double-foiled fins parallel to each other on a blank. He could well have been heeding Greenough’s advice about reducing distance as the fins were just six or seven inches apart instead of the standard ten to twelve inches. This, Purchase told Swellnet in 2015, gave the Duo “squirt” but without the “wiggly, fishy feeling in the tail”.

Neal Purchase Jr's Duo

And Now...?

When NPJ made his first Duo, he told Swellnet he looked at a standard twin fin with fins set wide apart and thought to himelf, "Fuck, there's all these other places where you could put the fins!" And that's just what he did. Because twinnies were sidelined for many years it means the design isn't exhausted, there's still lots of fresh ground to turn over.

Twin fins will never have the stability of, say, a Thruster, so they're not quite as versatile, however improvements in bottom contours, namely rocker, have added a bit more control to their handling. Even during his title years, MR still rode single fins in Hawaii, yet twinnies are now edging into bigger waves. Both Pete Mel and Anthony Tashnick have ridden big wave twins at Mavericks, while Torren Martyn has been pushing the step up twin in DOH waves.

However, it's down the other end of the board rack where the real cross-breeding is happening with twinnies being fused to every imaginable design feature and template, with chequered success. Yet, with untilled territory and eager experimentation it's not unreasonable to think that the above categories couldn't one day be added to.