madforsailing test: Topper ISO

The first boat to introduce many concepts now familiar to one design racing in the UK

Topper's ISO, launched in 1996, was the first of a new generation of mass production boats that provided high performance at a budget price. Featuring a now widely used crew weight equalisation system, the ISO was the benchmark for this new wave of fast, fun dinghies.

madforsailing’s Peter Bentley teamed up with Europe gold medallist Shirley Robertson, and they took the ISO out in good conditions (for a change) to give her the once over.

The test started well - it always does when rigging the boat is a doddle. In particular, the rudder assembly was one of the best we have ever seen. More high points for Ease of Sailing, the boat was as simple as any trapeze dinghy to sail upwind, aided by the powerful purchase on vang and mainsheet. The high boom meant tacking and manoeuvring was easy, stability and control were impeccable on all points of sailing.

At one stage during our test we had a helmsman who had never sailed a double-handed boat before, teamed up with a crew who had never trapezed. No problem, and even when we did tip her in (for the test, of course), the boat was easy to right from the capsize, and drained quickly.

A thumbs down though, when it came to trying to gybe. If we got the timing wrong the old sheet got caught around the jib tack bowsprit. The moulded non-slip provided good footing where it existed, but ran out in the places it was needed most - on the kick-off strips and the top radius of the gunwale, which made life a bit tricky.

In addition, the wings seemed to fill with water and we were concerned that high loads where the spigot enters the wing could be a weak point. The boom looked a bit short for the foot of the mainsail, which could cause problems in more breeze.

Apart from these, faults were few and minor. We thought the ISO was a clever boat, especially so, as the first of its kind. But time and tide wait for no man and successors and imitators have evolved.

While there are more than a thousand ISOs in existence and racing fleets are still alive, the halcyon days of this boat are over. Having said that, low cost second-hand boats are keeping entry level accessible and if there are a few racing at your club it’s an excellent way to get some good racing.

Rants Sorry, but past its sell by date
Raves Benchmark for an entire generation of boats

The Nitty Gritty

Ease of Sailing

Upwind, the ISO was as simple as any trapeze boat to sail, and much easier that most. The helm was light, positive and above all, very precise. A high boom made tacking and indeed all manoeuvring, simplicity itself.

Turning downwind, we found that control wasn’t a problem in this direction either. The large rudder did its job and bearing away in the gusts was accomplished with a light tug on the tiller. A little coordination between the crew and the helmsman never goes amiss, but it was possible to bear away with the spinnaker over-sheeted and the boat heeled.

Getting the asymmetric spinnaker up was easy, but gybing her was both simple and troublesome. If everything went well, it's no more difficult than tacking, but there's definitely a trick in the timing. If the old and new sheet were not let off and pulled on the right amount at the right times, the old sheet had a terrible tendency to get caught around the jib tack bowsprit. No doubt with time and practice it would cease to be a problem, but it left a question mark over the design in such a critical area.

A capsize didn’t ruin our day, the ISO was easily recovered from an inverted position. Once on its side it could be held there by just one crew member while the other cleared up. The spinnaker was easily re-bagged and when this was done the boat could be righted with just one person on the daggerboard. Once upright the boat drained quickly. The double floor was not strictly self draining - it's below the waterline at its lowest point and trapped water at very low speeds - but the slightest acceleration resulted in any remaining water moving quickly out over the transom.

Overall, on any point of sail, stability and control were impeccable and the ISO was an easy boat to sail. Although experience with a spinnaker and trapeze would be beneficial, it's by no means essential and this would be a good boat in which to get used to these new toys.

Systems and Layout

Rigging was a doddle - the mast sat on an adjustable step, supported at deck level by a space-frame-mounted gate. The shrouds and forestay were fixed by a clevis pin and that was about it, just the wings to slot in and we were ready to go.

The rudder assembly - one of the best designed and detailed we have ever seen - was secured by a single pintle and split ring. There's no way it could fall off, and best of all, there's no free-play. Adjustable for rake, the rudder could be locked in two positions - up and down - with a simple pull on the tiller. It was simpler and much more positive than most other systems. The daggerboard simply dropped into a shaped slot, and though none was provided, a lanyard would prove a sensible precaution.

A powerful vang and four-to-one mainsheet made easy work of the mainsail in all but the windiest conditions. Although there was never enough wind for us to tell, the boom looked a trifle on the short side (or else the mainsail foot was too long) and getting the base of the sail flat in a breeze with the outhaul could be troublesome.

The single-part jib sheet proved more than adequately powerful with the cleat beautifully positioned; the sail sheeted with ease. The jib inhaul and cunningham were also easy to adjust, but only from in the boat. Once the crew was out on the wire they either had to be left alone, or the helmsman had to be sent forward.

The asymmetric spinnaker system on the ISO used a single line to extend the pole and pull the tack to the pole-end. While the line was led aft, the cleat was positioned forward. With a little careful preparation, the helmsman can extend the pole but most teams will probably assign this task to the crew, leaving the helmsman free to hoist the sail. The spinnaker halyard also terminated too far forward in the boat for our liking - forward of the mainsheet - leaving the helmsman with something of a long stretch.

Great attention had been paid to the design of the one-piece deck moulding. Interior stiffening also served as foot braces for the helmsman and crew, and in some cases, as perfectly aligned mounting pads for fittings. Every fitting that did not have a natural resting place had been provided with a moulded-in pad, which had resulted in an all-but perfect lead for every control line.

The moulded non-slip provided good footing where it existed, but in the places where you need it most - on the kick-off strips and the top radius of the gunwale - the non-slip runs out, which made life a little tricky at times.

Performance

While the ISO was a delight to sail upwind, she was no slouch either, but it’s turning the corner to head downwind that - as is so often the case - gets the blood pumping. Once the spinnaker was up and sheeted in, the boat takes off. The marked acceleration was accompanied by a rise in the bow and the performance was impressive.

Build Quality

The ISO was constructed from glass and polyester resin, and appeared well-built by Reg White's factory in Brightlingsea, benefiting from countless years of experience gained building world class Tornados.

Fittings were almost universally from Ronstan, with mast and boom from Superspars. As one might expect, there were no problems. The Sobstad sails on our test boat set well and looked untroubled by the considerable sailing they had already endured during the season.

Anticipated Durability

The wings gave us cause for concern from the structural angle, and their implications for durability. High loads must inevitably occur at the point where the spigot enters the wing and as this was also the point at which the two mouldings are bonded together, one can only question how well the whole assembly will live up to rough treatment.

And it’s perhaps no coincidence that the wings on our test boat contained considerable quantities of water. There appeared to be a leak around the spigots and although the water seemed keen to get in, we were unable to persuade it to come out. Similarly, a small quantity of water found its way into the hull during our test, but this was easily drained away through a transom bung hole.

While there are exceptions in some of the parts, the execution of what was a quite brilliant concept was not all it could be. And you can expect that to be reflected in a slightly higher maintenance tariff for the ISO than with some of her newer competitors.

Quality of Race Circuit

Topper International organise the usual manufacturer’s open meeting circuit. There are plenty of boats out there, and enough still turn up for good racing, but the score here for the ISO would have been so much higher three or four years ago.

Value for Money

Difficult to get excited about the purchase of a new ISO, unless you’re already a deeply addicted fan, but a second-hand purchase is well worth considering if there are fleets racing close to you - just have a good look at the spigots on the wings before you buy!