JBoat J120 Review

Issue: July 2002
Manufacturer: JBoats 

It was the spinnaker that did it, the big white J on the red asymmetric kite carried by the J120 as it slid gracefully down-harbour. That letter J took me straight back to the mid-1970s and the first J24 in Australia. Rob Mundle was importing them and the first one had a red hull with a big white capital J on the side, in exactly the same script typeface as this 2002 model J120, on exactly the same red. Flashback. I still have the pictures, somewhere. Thank you, Mr. Kodak.

The J on the hull side of that first local J24 was part of the boat’s full name, “what a difference a J makes”, which has become a JBoats slogan. But at the time, I thought it had some sort of drug connotation, which tells us something or other about the mid-70s.

Now American Rod Johnstone has produced a big family of production yachts and it warms me heart to see the J24 still in the catalogue. Indeed, you can see the family resemblance in all the designs, as in any family photo album.

The J120 is difficult to categorise, which I usually find is a good thing. Johnstone has given it what the publicity material calls “more buoyant bow sections” to support the trademark asymmetric kites. “A lower centre of gravity reduces the need for wide, fat hulls for added form stability. A proportionally narrower hull, that slides through waves more smoothly, is more comfortable when cruising, and it is a lot faster”.

The words in quotation marks are taken from the publicity material, but what they show is that Johnstone has chosen to draw a moderate hull with a high ballast ratio (by current cruiser/racer standards) which should provide good form stability and obviate the need for having the crew on the rail all the time. These are seaworthy characteristics, wholesome factors (a bit like honesty, modesty and charity in human beings) which in these modern times we are expected to ridicule and thus to devalue. Sorry, I got carried away. Here endeth the lesson.

Why did the designer choose to work within these parameters ? Again, the publicity material tells a lot of the story because it emphasises the advantages of the asymmetrical spinnaker and thus the boat’s ability as a very fast passage maker with small crews.

Tough sailors won’t admit it, but everyone hates the conventional spinnaker. In light airs it is OK, because it draws you magically and gently forward in conditions where the other sails cannot. At most other times crews are at best wary of the three-cornered beast, and at worst downright terrified, because of its innate ability to get out of control and into terrible places, like around the keel.

I am not suggesting this would be the case with the owner of the JBoat 120 shown in these pics. But when I asked him what attracted him to the boat he said the big single factor was the asymmetric spinnaker. The asymmetric is a feature of the JBoats range – only four of the 13 boats in the catalogue do not carry the prodder, and all four are old designs, the J22 and J24 and two cruisers.

On the 120 the carbon-fibre prodder/bowsprit is controlled by a line, which runs from the bow to the cockpit through the handrail fastened to the cabin ceiling – inside the boat.

As well as those “fuller, more buoyant bow sections” Rod Johnstone had a few other factors in mind when drawing the boat. It is narrower than the current norm, maximum beam is close to amidships and the stern itself is not as wide as some.

The J120 is built in France using the SCRIMP method, a system which controls resin infusion into the composite cloths and minimises lay-up weight. This combines with the low freeboard to help keep centre of gravity low. Ballast/weight ratio is relatively high at 43 per cent and draft modest at 2.1m, reflecting the cruiser/racer role (there’s a 1.8m option). As a comparison the Sydney 38, admittedly not a similar concept, draws 2.65m. A carbon mast is optional on the J.

The below decks layout is straightforward, there’s nothing complex to add weight in the wrong place. The owner’s cabin is in the bow, a second double cabin is aft on the starboard side and behind the galley on the portside is access to a massive locker, big enough to be termed a lazarette in the classic sense.

Propulsion is provided by a keel-stepped mast supporting a near-masthead rig. The JBoat people organised a big crew for our afternoon out on the water. We had 10-12 knots out of the northeast on one of the last days of Sydney’s traditional Indian summer before it dissolved into a premature and nasty early start to winter.

North Sails’ Lee Killingworth acted as sailing master. He pointed out the areas he thought needed attention, including tightening the cap shrouds (which was later done), taping the shrouds together to cut windage and leading the cunningham forward a little to reduce load on the tack.

The boat marched upwind with real purpose, but we could not get a fix on speed, because the instruments were reading at one-second intervals, making it impossible to get a positive fix. Lee suggested dampening their activity slowing them down to four-second adjustments inshore, 8-10 seconds offshore. This reminded me that I must save up a little harder and get my own GPS.

Around the top mark and the crew popped out the red spinnaker (the smaller of the two, at 120 sq m). Then they rolled up the beautiful golden headsail on the furler, a sight that must give a sail maker palpitations. The owner pointed out that the ease of this manoeuvre saves time on the racetrack.

The weekend before they arrived at the bottom mark behind a fast competitor, went around outside him to give room, dropped the kite, unrolled and jib and were away upwind in the lead.

JBoat importer Mark Dent reckons that if you need to carry the spinnaker square, the best method is to ease off on the clew and let it float to windward a little.

Lee is up to the tactician to get the downwind tacking angles right, preferably by planning a short early leg, then a longer leg, hopefully in more pressure, into the mark.

Downwind we saw 8.5 knots of boat speed in 10 of wind, on a slightly steadier speedo. This is under the smaller kite; the big one is 165 square metres. Lee Killingworth later came up with another idea, a 700mm Spectra strop fitted to the spinnaker clew with the sheets clipped to its other end.

During a gybe, when a lot of sailcloth needs to be dragged across the headstay, the strop allows the clips to clear the stay fractionally ahead of the cloth, helping cut down congestion.

The owner likes to sail upwind with about one spoke of weather helm. Lee thought she would be at her best sailed bow-down, looking for speed rather than height to maximise water flow over a keel, which is shallower than that of a more race-oriented boat.

The J120 is the result of an interesting intersection of concepts. She is more than capable as an around-the-buoys racer. The owner of our boat reckons the Sydney 38s are faster upwind, while the J120 is faster down, but as they give her time under IRC she is always going to be competitive.

But the design makes much of her short-handed racing and cruising abilities, though as Lee Killingworth points out that big headsail needs a lot of winching. But if you were cruising short-handed you would wind some of headsail away on the furler.

In the United States and Europe the J120 races in one-design fleets, but as our boat’s experience has shown she is also a good Saturday arvo sprinter in mixed fleets. But you could also take her to the Whitsundays or Tasmania. If you wanted to cruise she would demand far fewer compromises on her crew’s part than most current cruiser/racers. She should be relatively comfortable offshore and the healthy ballast ratio means she should stand up to her canvas without early reefing.

She is quite light (displacement/length ratio is 145), but her conservative dimensions should mean no sacrifice of stability, whether lateral or directional. J120 designer Johnstone has found a niche and pushed it open perhaps a little wider than he intended.

To sit a J120 at the marina will set you back around $400,000. 

Story by Barry Tranter