How do I calculate the center of buoyancy on a top Assembly

Hi

I work with designing tools that use subsea. And I have a top assembly with lot of under assemblyes.

And my problem is that I whant to calculate the center of buoyancy.

I made a "quick fix" and but all parts in material water, but this is not a effective way to do it.

Please Help me to find a better solutions for find the center of buoyancy!

Kind Regards Jonas

SolidworksAssemblies