Photo by Carlo Borlenghi.

Photographs were what made the J Class famous. The camera has always loved their sweeping lines, and frozen the elegance of racing in an instant of silent beauty. But for the full picture, you have to hear a J at close quarters. These giant machines resound with the groaning noise of ropes under strain and aggression prickles in the air.

I felt it for myself aboard Rainbow as we closed in on the start line at the Superyacht Cup in Palma. Hanuman was approaching on port and, at the last minute, tacked right below us. The two yachts loomed together and, for a moment, as Hanuman swung out to the turn, were pulled menacingly together as if gripped in some forcefield. Our helmsman, former Olympic racer Mark Neeleman, coolly feathered up then rode back over our rivals as if Rainbow were no more than a dinghy.

Once the fastest yachts of their size ever built, the Js seized the public imagination on both sides of the Atlantic in a short heyday between 1930 and 1937. Today they are comparatively pedestrian, pushed to make 12 knots upwind and downwind. They are 180-tonne giants, slow to respond and loaded like cannons.

Yet a great resurgence has been fermenting since the 1980s, slow at first, then steadily gaining momentum. Of seven existing Js, five were racing this season and last. Two more Js are being built and another is in the offing. Refits have got more exacting and elaborate, and this summer the yachts have had the closest and most exciting racing their crews have ever known. More than 80 years on, the Js have muscled and swaggered back to the very forefront of racing.

The technology behind such a resurgence and the money being spent once again in the headlong chase for competitive advantage is a story for modern times.

In Palma Lionheart, Ranger, Hanuman, Velsheda and Rainbow are snugged up together stern-to at the dockside. The racing starts as late as 1400 after a long wait for the sea breeze to build, but the day’s routine begins early. This isn’t typical regatta racing, with most of the crew still shaking off a hangover at midday. By early morning a hard-core group of sailors, as well as some owners and guests, will already be out on road bikes, putting in the miles and comparing distances and times afterwards.

If you have a job on the Js, you are at the top of your game. The race crews are suffused with some of the biggest names in professional racing. Kenny Read, Volvo Ocean Race skipper and president of North Sails, helmed Hanuman; Ranger was steered by America’s Cup veteran Erle Williams, aided by four-times America’s Cup winner Murray Jones; Rainbow had Francesco de Angelis and Mark Neeleman; Tom Dodson was on Velsheda; and on Lionheart, helmed by her owner, Volvo Race skipper Bouwe Bekking was on hand with tactics and Andrew Cape with navigation.

Each of the Js takes 32 or more crew for racing and on average 12-15 of them are top pros brought in for each campaign. No one wants to be explicit about money; I heard wages typically run at between €500 and €2,000 a day, plus expenses.

Kenny Read speaks freely of the terrifically exciting challenges of sailing Hanuman. “These boats are fully loaded and on the edge. The loads are 20 tonnes on this, 25 tonnes on this. It was unfathomable two or three years ago that we would be sailing these boats to this level. It’s nothing short of terrifying at times.”

Toby Brand, skipper of Lionheart, says: “The runner loads are scary. So are the headsail sheet loads. But the most scary is the pole work. We’ve got an 18m pole and it’s very hard to handle. The most difficult and skilled jobs are co-ordination in the pit. On gybe sets at the top mark, we’ve got ten winches running. Everyone has to do the right thing, at the right time, at the right speed. We couldn’t do that without top professionals, that’s absolutely clear.”

Though pushed hard, the Js are essentially slow to react and can be hard to control. In the 1930s one skipper likened helming in light airs to playing the violin, but once the breeze got up, he said, they were ‘like a wild beast’.

The rudders of the Js, which have to remain in accordance with the original lines plan, are all highly loaded, with rather small steering arms. Long overhangs at bow and stern, and the leech of the mainsail set behind the rudder mean that sail trim has a huge effect; a J can stubbornly refuse to answer the helm if trimmers aren’t working in co-ordination.

“They are very physical boats to sail and everything has to be decided two minutes prior,” says Kenny Read. “I’ve never been on a boat where you have to think so far ahead. It takes a lot of time to start and stop 185 tonnes. You can’t turn easily, don’t accelerate; mistakes get hugely magnified. You are committed from many boatlengths away. You turn the wheel and the boat doesn’t start responding for eight or ten seconds. A lot of times, from a tack to full speed takes two minutes.”

Racing takes an icy nerve. In describing the close parrying at the Superyacht Cup, Read recounts an incident: “We had to dip behind Rainbow. The bowman gave me the thumbs down, but by that time it was too late to do anything. We missed [her stern] by 5ft.” It’s a chilling image, but Read continues cheerfully: “We had a tie in that race, so if we had dipped by another 20ft we would have lost.”

Although steering might occasionally be an act of faith, preserved by class rules, every other possible area of the Js is being modernised as rapidly as possible. One of the most surprising and impressive things, for me, was to see how quickly Rainbow’s spinnaker and headsails can be hoisted. Sails rise faster than they could be sweated on a small boat. Big hydraulics packages are standard now on the Js and most can power winches to raise sails to full hoist in first gear. Toby Brand, skipper of Lionheart, explains matter-of-factly: “We can do 250m of line per minute.”

The pace of evolution in the J Class and advances such as these, can be directly attributed to the input of professional sailors, who have cross-pollinated technologies from other areas of sailing. Sail programmes have been revolutionised and are continuously being developed. Hanuman came to the Superyacht Cup with a new dark [grey?] headsail, a so-called 3Di ‘raw’ sail with the same carbon structure as the 3Di sails now ubiquitous on top racing yachts, but covered by a thin paint spray rather than taffeta, and said to be a lot lighter.

Light, low-windage carbon rigging has become standard. This year, Lionheart was sporting Carbo-Link standing rigging and had a fibre optic load sensor incorporated in the headstay to confirm design loads and analyse the load variation in head seas.

A great deal of work has been done on rope technology – the line speed of the winches is so fast that rope coverings can melt on the drums. Different mixes have been used to make sure sheets and halyards aren’t too slippery or too sticky.

Designer Jeroen de Vos from Dykstra Naval Architects worked on the designs of Ranger, Hanuman and Rainbow, as well as refits of Velsheda and Endeavour, and is one of the leading J Class experts. He says: “These boats don’t follow the trends. Small-boat technology immediately comes into the class.”

According to Kenny Read, the biggest gains have been made by reducing rigging weight, making the boats more stable and allowing weight to be stripped out of the ends of the boats. Deck layouts have been changed on several Js to cope with the increased loads. Other incremental gains have been navigation software, says Read: “especially time and distance to the start line. That has narrowed the gap between the OK starters and the great starters.”

“The Js are pushing every fashion of the marine industry as hard as any class has ever done. And it’s not about money, it’s about competitive advantage,” he continues. “That is why, for me, it’s so cool.”

The desire for a competitive edge inevitably leads to a search for where corners might be cut. Under their rules, a J Class yacht has to have a fitted interior, but there are whispers that new owners could be looking at a compromise. Jeroen de Vos thinks: “There might be a tendency to put less interior in a boat. How complete it should be is a matter of debate, and that is very sensitive in the class. But you have to see it as a normal evolution. New people will come and they will push the limits.”

Despite the high costs, the injection of new technology and skills that has propelled the Js to some of the most intensely close racing in their history is, in turn, casting a spell over new and potential owners. “These are exciting times for the class and what’s driving it, whether the boats are old or new, is that the speeds are the same,” says Lionheart’s skipper Toby Brand. “We are all fighting for very small gains and that’s making it fun. On any day, any boat could win.”

Fun though it is to race the Js, there is a palpable edge to it. This is serious. “These are all competitive people and the owners are by definition competitive,” Toby Brand remarks. Happily for him and the crew of Lionheart, they came away as the winning J in Palma.

Kenny Read admits that losing a race in the Js is painful and says: “None of these owners became as successful as they are by doing anything half-assed and getting beaten. But it is huge fun and the owners are having a blast. This is high quality, high-powered racing. This is as good as it gets.”