Level racing or Formula 20 racing… What are the practical differences?
ISAF 2002 ratings.
Nacra 6.0 SE .94 I don’t know how this compares to a Nacra 6.0 NA
Nacra Inter 20 F20 .94
Tornado new rig .94
Hobie Fox F20 .94
The ISAF F20 rating assumes a carbon mast.
Main
F20 rating = 18 sq m Inter 20 lists main and mast as 18 sq meter (194 square feet)
US I20 will measure into iF20 class. So… it is not an oversized mainsail
Jib
F20 rating = 4.85 sq m US I20 lists jib as 4.15 square meter
US I20 will measure into F20 class.
Spinnaker
F20 rating = 25 sq M US I20 lists spin as 23 sq m
US I20 will measure into F20 class OR they can upsize and use a Tornado chute!
Tornado is not f20 compliant because of the 10 foot beam.
However… the boat carries less sail area then f20 rule allows and matches their rating.
ISAF measurements
Main 16.87 sq m Not the 18 sq m allowed.
Jib 5.2 sq m Over the allowed 4.85 sq meter.
Spin 25 sq m equals allowed sail area.
Total upwind sail area Tornado 22.07 sq m versus 22.85 sq meter for a iF20 legal boat.
Bottom line… upwind the if20 boats carry 8 sq feet more sail area. Dowwind they are equal.
US I20 carries more sail area upwind then Tornado. But it is insignificant
Upwind US I20 22.15 sq m versus 22.07 or 1 square foot additional sail area.
Down wind, the US I20 is sacrificing 2 sq meters of sail area. or 21.5 square feet of sail area. This amount of sail area is about the same as used by the F18 class to equalize differences in crew weight.
Carl Roberts has claimed that the Struble/Oliver win over the I20’s at the Hogsbreath race was attributable to 10 foot beam. A more reasonable technical interpretation is that in a down wind race, where beam is of less importance, the 21 .5 square feet of additional sail matters! Or the most likely explanation is to give credit where credit is due to the sailors on the T cat.
This conclusion is also supported by the Nacra 6.0 NA results over the I20 fleet. These sailors carried 17.76 square feet more sail area upwind then either the I20 or Tornado. Down wind the smallest chute they were likely to carry was the 32.5 square meter New England class legal chute (350 sq ft). This sail is 80 square feet larger the iF20 rule..
In summary, the Nacra 6.0 NA’s are sailing with almost a 100 square feet more sail area then a Tornado and almost 120 square feet more sail then a US I20. Randy Smyth has noted that sail area is king and he designed the largest practical chutes for the unlimited worrell racing of several years ago.
Seems to me that level racing would be achieved with all the 20 foot boats standardizing on a 25 sq meter chute as the iF20 rules allow!
Mark
What results in New England are you referring too? Well there isn't any. A 6.0 with NE spinnaker has never sailing against an Inter 20 around the buoys in the Northeast. The first time was at the Spring Fever. Rick sailed well but I watched him do everything on the boat. He put the spinnaker up himself and took it down. I don’t know if he did this every time. Add a little wind and this will change things.
Here are some results for last weekend in a 6-mile distance race. It was a reverse start. The correction was at the start. The 2 6.0’s started 3:36 ahead of me.
N6.0SP Bliss 341 2:26:40 Was using Worrell Spinnaker
N6.0SP Anderson 343 2:27:24 NE spinnaker
I20 Moore 252 2:27:53
Hi Barry
I was refering to the Hogsbreath 100 this year ie a downwind sleigh ride this year.
The only race that I can think of where the 6.0 sailed against the I20's was at Barnegat Bay last year. Garrett Norton tried out his snuffer for the first time along with new crew. Garrett had his moments against the I20 and his inital take was that he could be competitive around the buoys. (Spring Fever.. could of ... should have allowed a fair comparison... but)
I am not sure, but I beliieve the Nacra 6.0 SE has a smaller sailplan and probably a 25 sq meter chute in the EU.
My point is that if you believe the ISAF rating system is fair ... then its possible to configure the three major 20 foot boats to race scratch. However, this will require limiting the spin sizes (or increasing the chute on the I20 if you want) to 25 sq meter.
BTW, I sailed with Eric Anderson at the Statue race last year. I managed the 350 sq ft chute without a doubler since we were in hot pursuit of of Bob B and Garret and it was a handful. In my opinion... 25 sq meter is plenty around the triangles because you can't afford to use a doubler.
Take Care
Mark