Imagine what it happens when you take a catamaran 15 metres long constructed of carbon fibre composites, motivate it using two, engines rated at around 1200 Horsepower (895Kw) each and throw in sea swells and wind gusts on the open ocean. Now think of what to takes to model that in CFD to ensure a fast but stable design. We invite you to surf on to see some early successful results of ongoing work.