Swift Solo

Actually Dennis,

It's a bit more like the 49er in terms of underwater surfaces (much less rocker--proportionally more beam and a bit more concave chine line forward).  The Swift was originally designed as a single handed trainer for 49er sailing.  The height of the deck step and pitch of the wings are similar to the 49er as well (not rounded for hiking like the 29er).  As pointed out earlier, above the chine/waterline, it gains volumn much faster than either the 49er or 29er.  I did this to minimize bow diving because of the large masthead kite.  It's hard to see in the photo but the chine is a bit concave from the bow to station 6 (just forward of the DB)

To be sure, I owe both of the Bethwaites for much of the design and for many of the rigging ideas.  Frank's High Performance Sailing is a brilliant piece of work when you combine it with more recent design development.  Julian has been a big help to me as well and I believe that he and Paul Beiker are the brightest of the current skiff designers by a significant amount.

An observation and prediction:  future gains in skiff design will come from integration of systems not simplification.  Much more sophisticated systems will be developed that will make rig control simplier to acheive.  A single string adjustment that will accurately and proportionally tighten, primaries, loosen lowers and caps, loosen the jib leech while tightening the jib luff right up the wind range is just around the corner.  The Swift has a sail plan and rig that allows trapping in 5 knots while maintaining control in 25 knots with a single suit of sails.  Because Swift rig control is not "One Design", we are working hard to simplify and integrate rig control adjustments (it's hard to adjust turnbuckles in the middle of a race when the wind velocity changes radically--especially single handed.  It's even harder to pull out the boat bender in the middle of a race)  

Bram

Jim C said

“And a wider deck beam boat will always be faster than a narrower boat until it gets way into major control problems”……

Actually a wider deck beam will always be slower and harder to manage until the wind velocity / sail area exceeds the available righting moment.  The real problem with wide beams in single handers occurs in light to medium gusty winds.  Once you are overpowered, you can stay out on the wire without moving in the lulls by simply de-powering the rig and playing the sails.  This is especially true with the Swift because the sheeting system and the on-the-water adjustability. Eight inches of sheet play will neutralize nearly any gust.

“So there's some evidence to suggest that "too wide t handle" is not really kicking in at Musto Skiff/RS700 beam…...”

 Again, too wide to handle occurs at the full out traping threshold—around 10 knots of breeze in many single handed trap skiffs

“But I'll bet its possible to go faster than any of them. I also am beginning to have my doubts about very big sails: I have an idea that dinghies are starting to approach the sort of performance area where efficiency is becoming more important than brute power. After all how much rag is that AC carrying uphill?”

No doubt that you can build a single handed trap boat that will go faster than the Swift.  The real question is—will it go faster and remain tactical or will it simply be another “bang the corners---one trick pony” that tacks and gybes like a cat?  The picture is of Charlie McKee in USA 001 (the prototype—still had cut down 49er mast and sails).  After just 45 minutes in the Swift Charlie could gybe from wire to wire faster than any boat / sailor I’ve ever watched.  The closed wing / high boom /  and run through deck contribute to making the Swift a boat that is so tactical that you need to play even the small shifts if you expect to win.

I suspect that the AC would be faster in 8 knots of breeze if it had more sail area?  Remember, the vast majority of major regattas worldwide are held in winds that average between 5 and 15 knots.

Bram