The Optimist Dinghy

This design has one of those histories that sound like a lot of fun, the designer, Clark Mills, is said to have done the design drawing on a scrap of paper. This was around 58 years back and he lived until just last year, to see his single design out sell all the other dinghy classes combined. He also gave his design to the world and never charged a design fee, allowing what was to become a world wide Optimist Association to run and control the class.

That first boat was made from two sheets of ¼” waterproof, or marine, ply plus some Meranti cleats and screws and glue to hold it all together. It was either clear varnished or painted with house hold lead enamel paint. The class grew and grew. The boats lasted for years and many of those old boats still exist. Then came what was to be a very large change in the class rules. The allowance and introduction of GRP (fibreglass) which more or less sent the older wooden boats into history; why?

A modern Epoxy/Plywood boat from one of our kits. It raced in the SA Nationals in 2005. (click images to enlarge)

When our daughter was learning to sail, she was about 12 or so. We took her to the Imperial Yacht Club, which sails and races dinghies on a lake near our home. There we saw the old plywood Optimists but also the newer GRP boats. All the top kids wanted to sail one of those, saying they were better boats. If more money buys better they had to be. Prices for those Imported boats went as high as R40,000 I was told, that’s US$6666, it sounds impossible I know but fully imported boats have to be shipped and when they arrive a high rate of local import duty has to be paid.

At the time I had an idea to make a plywood Optimist for Janet as she was proving to be a fine little sailor. Plans were freely available from Hans who was in charge of the association here in the Cape. So asking my good friend Andy, of the local North Sails loft, what he thought about the difference he simply told me the GRP boats were better as they were stiffer.

Asking why I was shocked to hear that the GRP boat has a foam sandwich bottom! I said it was easy for me to construct a plywood boat in the same manner? That he said would not measure so would not be allowed to compete. As I could not afford the expensive GRP boats and there was little point in building a plywood boat that was not competitive, so at that time it was the end of the story where plywood was concerned.

Well, all is not quite as it seems: I was not the only one who had assessed the situation and in 1997 a group was formed to re design the plywood boat - enter THE PLYWOOD/EPOXY BOAT! They started with selecting very light Occume Marine Plywoods; one sheet of 12mm and one sheet of 6mm. This was a large departure from the previous plywood construction. The 12mm sheet became the bottom and in a stroke of good design they had equalled the foam sandwich stiffness. By not using as many Meranti wood cleat and all the screws but just epoxy and glass tapes they saved lots of weight and now we had a boat that was both light weight and stiff.

The wood/epoxy Optimist as a complete kit

Enter CKD BOATS

We were more than pleased to be asked to accept an order from the Knysna Yacht Club, which is a round 250 miles North East of Cape Town. The original minimum of five boats went to seven, then nine by the time we closed for the annual December holidays. There was a catch with the order, of course. The RSA Optimist nationals were in mid December - we had around six weeks to develop the design but also leave the mums and dads enough time to build the five kits required for the event.

Most of our other work was shelved while we got stuck into the program. The official plans arrived; the plan of action was to have our CNC shop man, Sean, enter all available sizes off the drawings into his PC while the rest of the kits materials were being completed. This includes pre shaping all of the Meranti wood parts - making the assembly a lot simpler.

We cut the first set of panels in a lower cost exterior ply, reasoning that if we found mistakes we would not waste valuable marine grade plys. This was just as well. The boat you see here had to be taken apart some five times, as the plans do not match the strict specifications. One dimension was out by 14mm (5/8”). Each time the trial boat was rebuilt it was then measured again, any changes were then given to Sean and he changed his CNC files to suit our changes. It’s hard to understand that the plans do not match the specifications laid down by the class rules!

Mike, using his body weight to shape the 12mm lower panel into our specially designed builders jig.

Once we thought we had things right we had the boat measured by an Optimist official who found it correct.

This is quite simple: you unscrew all the hull sides from the 12mm thick lower panel, lift off the top of the boat as the four sides in one unit, apply glue, then screw it back together. You then glue and screw each corner, one at a time.

The fully detailed instructions we supply give you a step by step system to build with. The only person who ever had problems was a guy who later admitted he never read the plans. We sent him twenty pictures instead - the pictures are in the builders book anyway. Once the boat is glued together, the inside panels go in. We supply extra bulkheads as spacers. These are later removed but only when all the Meranti Joinery and side rails are fitted.

The removable bulkheads are either side of the lower central and fixed bulkhead.

We made the Knysna Yacht Clubs handover deadline with a day or so to spare, then the rush was on for mums and dads, helped by their kids to make up five of the kits, as they had already sent in their entries for the SA Nationals at Hermanus Town, about 100 miles north east of Cape Town. They went into the Novice section and the CKD Boats kit boats finished four out of the first five places. We missed out on third place!

One really great thing that came out of the event was that our boats on average were all 750 grams lighter than the far more expensive GRP Dragon boat from China. As the new wood/epoxy is as stiff as a plastic one and our boats weigh less, there is nothing to be gained by spending more on the plastic boats?

An indication of prices at that time.

CKD Boats kit, complete with Optiparts Mast, Harken Deck Pack, North Sail…….R8450

The same gear but a Dragon GRP hull…….R17,500

Which in US$ terms is around U$1408 and a massive U$2917. With our option you have to get your hands dirty a little though!

Lots have now been built and we have happy customers around the country!

These boats are lightweight, fast and stronger than any GRP type boats. They are easier to repair as well.

Vince trying his kit build out.

Racing - as they were meant to do.

Roy Mc Bride - Founder - www.ckdboats.com
email - kits@ckdboats.com
Cape Town
South Africa

More articles by Roy McBride:

• Sofala, A Big Little Ship
• Oil Changes
• Do Yachts Need to be so Expensive?

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