are the boats about equal in dealing with lumpy water?

Let's just imagine that for the purposes of this question, the wind direction/speed were to put the boats at equal footing

The Nacra 20 owes the F18 3 minutes 56 sec per hour of racing under SCHRS. (Scooby... is that an official rating/)

It's a little less under Texel of 3 minutes 34 secs per hour.

Under USPN the difference drops to 3 minutes (2min 59 sec)

The rating system differences are swamped by the prevailing wind direction and pressure.

As Smyth proved over and over again... you need to have an advantage in the light air. In time on time racing... you just can't make up the time when the breeze is on.

It would be interesting to see what would happen if the N20 sailplan had been developed to the degree of the F18's. I bet they would have the same low end gears.

Likewise, if the breeze is on... the 20's really want extra beam oh... say about 10 feet to take advantage of the power....

This is a classic horses for courses game! Who knows what mother nature has in mind next.

Yes. It's official if it is on the site.

The rating detail is here

F18's are 8'2.5" beam, correct? so 98.5" vs N20's 102". Maybe about 3% difference in righting moment? I had a N20 and sold it, partly due to the complexity of rigging for a somewhat-casual sailor like myself, but partly also because of Performance's insistence on one-manufacturer "one-design" sails. This may be eased a bit now, I saw a report of the "Skip Elliot" spinnakers failing. Back in ought-seven, Elliot/Pattison was the maker of record. Anyway, hope the best sailor wins and nobody gets hurt out there.

Andrew the F18 is 2.6m wide same as the N20. the n20 is 3 kilos lighter and has a bigger main.

What weight are the N20 boats sailing at?

Well this is what they advertise... the actual weight might be something else.


http://nacra.us/N20/n20index.html

Length:20' (6.10m)
Width:8'6" (2.59m)
Mast Length:32' (8.13m)
Weight:390 lbs. (177kg)
Mainsail with Mast:208 sq. ft.
Jib:53 sq. ft. (4.15m2)
Spinnaker:270 sq. ft. (23m2)
Construction: vinylester foam, sandwich hulls

This is nothing like what the boat we have measured for SCHRS.

All up weight is different(we have a heavier boat), Spi area different(we have 25sqm vs 22), Jib Different (4.72 vs 4.15), mainsail similar.

however there is not need to panic.

i just plugged the other values into the rating engine and the reduced sail area and reduced weight changed the rating to 0.938 instead of the measured boat at 0.939 so I do not think this will make a lot of difference.