I forgot another exception. Yellow pages and Macquary Innovation. These are planing contraptions for an all out speed record. But they are very different to a normal catamaran and mostly in the sense that they are very wide and don't have long hulls at all. Yellow pages and the other have three hulls which are all pretty small and the leeward ones are in line with a significant gap of water between them. These will remain "flat" very well due to this overall configuration, but makes it very different to a normal cat like the Tiger Shark.

Wouter