Monday, June 4, 2012

Didi 29 Retro!

A Wolf in Sheep's Clothing!
I wonder if musicians can appreciate written music before they have heard it played? I guess they probably can otherwise how would they write it? Anyway - this is the first boat review I am prompted to do on a boat that has not actually been built yet. Its also the first one for which I have been prompted to include an exclamation mark in the name! You'll see what I mean . . . there will be more to come when we see it on the water.

This is an extraordinarily interesting design from a number of perspectives. When I first saw the outlines on Roy McBride's blog I responded with a short email commenting on the design which he immediately published, and the interest in this design has been immense.
Click on the pic above for an animated 3-D view on YouTube.
Note the planing underbody, powerful, high-lift keel, and the deep high-aspect rudder. Only the plum bow and the transom-sheer can be seen above water!

Classic topsides including the transom sheer, vertical cabin sides, classic bowsprit, and slightly raised bulwarks up front. Her moderately slender profile gives no further clues to the sportsboat lurking in her!

For all the world she looks like a classy and humble old gaffer. Originally gaff rigs had loads of sail (and sails) spread fore and aft on the hull as early technology couldn't support tall masts and high point-loads, or deep keels for that matter. So this rig is capable of hiding a vast sail wardrobe "at the ready" in a low-tech guise. Never mind the powerful assymmetrical on the 2 m bowsprit. Never mind the full roach gaff main, or the two headsails which can be used seperately or in combination, and sheeted right into the centre if desired . . . 

Space below is limited but practical and well used, with decent heads and galley. Headroom is limited at 4:3" - about the same as an RCOD or my Flamenca - but enought to get about in. Enough crew-berths for an offshore race, or family weekending at a pinch. Compared with say a Pacer-27 she is cavernous!

When I first saw this hull it struck me of the old days when people placed V8s in a "stock standard" looking VW Beetle, and proceeded to blow the socks off the Ferrari's of the day! While that is an unfortunately crude analogy, the element of suprise compares very well!

As you can see, the underbody of this yacht is pure sportsboat (without excessive beam and fat stern) - the flat planing sections at the back, long waterline, high aspect (bulb) keel and rudder, deceptively firm bilges, and quite easily-driven (slender) at that. Built from the well proven DiDi-26,  the dynamics are well understood, with the advantage of quite a bit more length. Construction from ply will keep it suitably light and very agile.

The topsides have all the styling cues of a proper old gaffer. Hahaha! This is where the fun really starts. Gaff-rigs, even in their old original form, are amazingly capable rigs. The well known sailing author Frank Robb wrote a convincing argument explaining his preferences for Gaff Rigs some years ago. In recent times, modern materials, technologies, and the IRC have made a clear winner of tall Bermudan Rigs with dominant mainsails however. Can this design change the state of play again? Probably not, but its going to be quite an interesting race in this example, especially if IRC is left out of the picture.

Off the Wind
Firstly, Gaffs are damn fast downwind, and in in all points except hard on the wind. Their centre of effort is much lower than a Bermudan rig, and the roach much fuller. They produce awesome power and penetration, whilst also being more controllable in very heavy winds - as the mast is far shorter -  so avoiding the instabilities of tall masts once they are over-powered or start rolling. More broach-resistant by far - which means you can drive quite a bit harder . . . On this 29 Retro, there is the small matter of a big assymetrical on that 2m bowsprit. Given the usual 25+ knots in the Mykonos race, I would be tempted to try it under the spinnaker alone. It will be astonishingly stable using just the bag, which is pulling far ahead of the centre of drag, whilst generating lift on the bow. As such, the rig is inherently stable, it shouldn't be able to broach at all . . . the planing underbody won't produce much argument from the hull, and the combination should be good for > 20 knots in the right hands!! Can't wait to see its first Mykonos race. Even with the main up, the gaff main is far more stable off the wind than its Bermudan counterpart, being far lower. Notice the spars are all carbon-fibre . . .

Light Airs
This rig offers a lot of canvass in many combinations. The hull is easily-driven and light. One tends to sail slightly looser in light airs anyway, so the gaff main will cope well. The two headsails could be flown in combination(s). It should be a killer.

Upwind in fresh conditions, Round the cans.
Established wisdom on gaffs suggest this will be its weakest point of sail, but I really suspect this is where this rig will offer its biggest suprise. Perhaps even the designer will be suprised! Why? Well typically, the fastest boats upwind are smallish, light and beamy, and benefit from generous crew weights on the weather rail. They generate huge power from the relatively high righting moment against the heeling force. L26s come to mind, and suitably crewed Pacer-27s, Melges 24s etc etc. Even Miuras are quite impressive in this role. But don't forget the RCOD. It's a slender hull, heels like hell, lacks power in the rig, but makes good angles and is easily driven. It moves nicely through a sharp chop on the water. Somehow they get to the next mark faster than you expect. This 29 Retro will do all that and more. The hull will track and point beautifully. The high-aspect (bulb) keel is good for plenty of lift, and its depth will provide good power at a fair angle of heel. The headsails can be sheeted extremely close as they don't clash with the stays. This gaff main is a very neat example - I don't see why it won't come in as close as a Bermudan main given the way the top-spar is fixed? The lower centre of effort is an obvious advantage. As a helmsman, in fresh conditions, I would optimise the headsail(s), use the main primarily to balance the helm upwind, and see how she goes. In lighter conditions she will reward a looser angle of sail favouring hull speed and this may be the way to get a good VMG. Some time with a GPS will be useful. One way or another, there is a lot more to this rig upwind than meets the eye.

All in all - this is going to be a very interesting boat to sail and own. There are many races she will do extremely well in, and will suprise the fleet in all circumstances. The beautiful looking traditional element is a joy to any yachtsman. She will dominate the bartalk, the press and the photo galleries. Having driven camera boats at various regattas I can just imagine Trevor Wilkins and Brenton Geach chasing after this baby, with or without the sponsors logos! I wouldn't want to be on the club handicap committee after the first race . . .
To add some further interest, I don't think this boat will need much in the way of winches - and the standing rigging will be very clean and simple. There is no need to get on the foredeck, and she will be easily handled by two people, making the element of suprise even greater!

This going to cause a lot of head scratching with sailors and designers alike . . .

Part 2 will come when we have seen her on the water - in 2013 I guess.
See Dudley Dix's Blog at
See Roy's blog at for details on the build as it happens, and the kits.

LATEST: Dudley has released a new rig for this design:

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