@MBounds and HRTsailor
Thanks for the info, really made everything clear as water.
I was only trying to do the computer thing because I'm studying Naval Engineering, I'll have to do it anyway when I'm taking "minor ships design".
Well, since you're studying Naval Engineering, I'll let you in on a little secret.
Computers are only a tool. They may not be the best or the fastest way to figure something out. Ships have been around a lot longer than computers, and Naval Architects did just fine without them for thousands of years. The real expert knows when and what tools are appropriate.
For a very quick and dirty way of finding the centroid of an area (which is essentially what the Center of Effort / Lateral Resistance is), you cut the shape out of cardboard or other stiff material and balance it on a pin. No computers involved.