Basically, I think the nacra 500 to be the best entry catamaran available today. And the fact that this comes from the founder of the F16 class, says alot. I truly think it surpasses teh Hobie 16, SL16, Dart 18 and a score of others. That is from a design point of view and the way it sails. Its only drawback is that Nacra formed a serious class around this design and as such their is no class racing as the Hobie 16's and Dart 18's have. I also think that the Nacra 500 should have been chosen as the youth boat instead of the SL16. It is just better and its predessor Nacra 5.0 is similar enough and sold enough the world over to immediate have a class the world over.
The Nacra 500 looks modern and is modern with its squaretop mainsail and blade jib. It also takes a spinnaker upgrade quite well. The platform is very stiff (much more then the H16 and Dart 18's) and this improves it feel and sailing behaviour. Is has alot of hull volume and carries weight suprisingly well. It shares the same rudder setup with the Nacra F18's (and the same rudder stock concept with nearly all F18's) and as such is very easy to operate. It is also twin trapeze and the total weight of 150 kg makes it light enough without being high tech. It can be righted singlehandly by an adult that (I suspect) is at least 80 kg.
And most of all it is a relatively inexpensive boat to buy new. I think they go for 10.500 Euro in Europe in their basic setup. Probably ending up at 12.000 Euro's with some of upgrades.
I honestly feel that the Nacra 500 is a great design.
However I wouldn't go as far as to say that it is the best for singlehanding. However, it is certainly one of the top candidates; better then the Hobie 16 for example.
Most of the comments above also apply to its predessor Nacra 5.0
What do i need to change?
I don't really understand what you are asking here. Please explain
Wouter