Fastest dinghy?

I find the inertia of a aluminium mast significant compared with carbon, and I'm talking of masts of only 7.5m, but the weight of the mast is significant and limits the rapidity with which I can round up onto a beat from a fast reach.  However it also works in my favour when bearing away in a sudden gust since by driving the hull under the mast it counters the heeling force of the gust.  Does that make sense I could explain in more depth but it would take time?

Anyone up for making the 'ultimate' planing cat? Strap a couple of 49er hulls together, rig off that new Jo Richards 30 footer, hey presto!!  overpowered in 5 knots, just like the stuff on lake geneva. 

watching that all i could think of was blur's song 2

Hey Simon, while there's little doubt the cats fly around a course, don't be so sure they're much faster downwind than a big skiff.

It's hard to say without seeing a T up against a big skiff, which I haven't done for a while, but compared to a board they both seem similar in pace. A cat sailor I know (a top skipper in Taipan 4.9s, arguably the fastest 16' cat around, and about 5th in the F 18 worlds as crew) reckons a Cherub can beat a Taipan downwind in a breeze.

A couple of times when I've been cat racing I've taken the board out before or during races. It's much easier to stay with the cats than it is to stay with the 16' skiffs down the bay. Of course, the speed of a board v a boat varies enormously depending whether we're powered up or not. In about 10 knots, the 16' skiffs seem similar upwind to the IMCO board, but the IMCO board is slower upwind than a Nacra 14 sq (baby Inter 17) sailed by a world A Class champs runner-up. Downwind, the board is slightly quicker than the Nacra, way slower than the 16' skiff. And the 16 is only about as fast as a 14' skiff.

In a good hard breeze, even my old slalom board can blow away a good A Class downwind (and when I say "good", I'm talking about an A fleet that attracts guys like 3 time world A champ and current F18 world champ) yet in the downwind race on the bay, FW boards are similar in pace to an 18' skiff. The FW boards would blow my slalom board off the water on a square run.
 
Many years ago, the Tornadoes (some with kites) raced the 18s and a C Class cat. The first T was just 17 seconds ahead of the first 18. Sure, the Ts have improved since then, but so did the 18s. In fact the top 18's chaseboat (IIRC) measured the 18's speed down the squares as faster than the C C lass (Victoria 150, the world's best at the time).

OTOH, I do know T sailors who reckon they kill 18s. Then again, those same T sailors reckon their yardstick with the new rig should only be 3 points faster than the "classic" rig; so either they're exxagerating the speed improvement or they're talking B.S. to the yardstick guys.

I'm not saying the cats don't fly upwind, but have you lined up against a good 49er or 18 downwind? You may be surprised.

And of course, when it gets to real smallboat speed nothing comes close to a board (apart from YPE which is strictly a flat-water one way machine, which is only fractionally quicker than a board that can sail both ways and in rough water).

Simon, as far as top speed is concerned the yardstck means next to nothing. The yardstick represents vmg round the course averaged over all conditions. The Cats are superb moderate wind machines, especially upwind, and they do get round the course very fast. But downwhill when the wind gets up the skiffs just get faster as the multis top out.

Do you know Steve Clark (the owner of Cogito, the top C Class) claims that the maximum speed he's ever got out of Cogito is 23 knots. That's standard skiff territory. But in 8 knots of breeze Cogito will do 19knots, and there's not a skiff in the world that would have a prayer of living with that.

I don't often get to race against cats, but the other year I got to race against the top of the Unicorn fleet. They slaughter us round the track because they're so fast upwind, but in a f4 downwind the Cherub is easily quicker. The only spinnaker cat I've ever lined up against is a Spitfire, and I have no idea how good the ones we happened to sail next to were, but the Cherub was the same speed offwind in F3. Upwind again was quite another matter, they're far faster.

One of the most impressive sights I know in sailing is something like a big Nacra hurtling upwind in a breeze with a feather of spray from the leeward bow. Ye gods they are quick. But downhill they don't go that much faster in the way that my Cherub, for instance goes more than twice as fast (that's measurable in real numbers) on a flat out reach as on a beat.