Hello all, In a classic example of putting the cart before the horse... I have designed a underwater Vehical in a CAD program I would like to test. I have no educational physics background of any kind. I just had the idea and did it. Now that its done I would like to begin to understand how my design will behave. And what design changes are best to make. I am currently down loading all the EFD videos from the sticky, and understand that I must review these before continuing. I also understand from a cursory viewing of some of the FD videos that a Physical Model will be needed no matter what. I am capable of that, and have a scale model in mind. I have no idea yet where I will test it. What I would like to know is what is the best way to get my cad model into an underwater simulator software program, if possible. And what the software is called. Also any other input on how I should proceed is welcome, Thx.