A Un-measured NACRA F18 can not be considered an ISAF Multihull or an International F18 for that matter. (I think it was a poor decesion to use the F18 monniker on that boat, but MARKETING RULES) Once you measure and certify it then it falls under International FORMULA 18.
The one design Tiger HAS recieved ISAF Multihull status and therefore can (according to ISAF) hold Worlds Championships.
To add another spin on this a one design Tiger DOES NOT qualify for ISAF Formula 18 status UNTIL it is measured and certified.
I'm not sure I agree will ISAF's absolute stand on World Championships, but it is the way it is.
Besides if you are not going to compete in ISAF or US Sanctioned events it really doesn't matter.
