0AndyGadgetBest Answer 8 years ago ReplyUpvoteHow big do you want it? Single hull or multiple hull? Lake, river, sea? Scale model or your own design? How is it to be powered? What is your budget? What skills do you have? What materials and tools do you have access to? And the critical question . . . How much research have you done already? Once you can answer the questions above and come with up with a few ideas of your own you will be able to ask sensible questions here.