I may not know how exact because i have never used that program before but however i have noticed that your ship contains just blue and yellow, so here's a tip try to add different color to the ship to different parts of the ship e.g start off with making the ship white and then adding different colors to it i.e water line-redish kind of a crimson red, maybe add some algae to it around the water indicating it has been in the water for so long.One main important thing is to have a picture of the model you are going to make to so you can follow up that model like the one below, its quite nice to make,just take your time.Se if it will give you an idea, on the link below you should find pretty much everything you need to know about this particular catamaran.
http://images.google.co.nz/imgres?imgurl=http://www.pedigreecats.com/3ID/23-2.jpg&imgrefurl=http://www.pedigreecats.com/&h=328&w=640&sz=39&hl=en&start=147&um=1&tbnid=NRyUib6Q8SzvKM:&tbnh=70&tbnw=137&prev=/images%3Fq%3Dcatamaran%26start%3D140%26ndsp%3D20%26um%3D1%26hl%3Den%26sa%3DN