LCG and LCB for Planning powerboat

Hello everybody,

I am trying to find LCG of powerboat. I have 3D file of the hull and actual trimmed waterline. From those data, I found displacement and actual LCB. Can I say this LCB is real LCG of this boat? I think the boat has trim so location of this actual LCB makes balance for the weight of the boat. So we can say LCB is exactly actual LCG of the boat. Please give me some idea about this issue.
Thanks.

 

Yes, LCB = LCG. If these two centres were not the same there would be a trimming moment turning the boat around its transversal axis until there is momentum equilibrium.

 

It depends on the coordinates system used. If it's fixed to the 'earth' -so the vessel trims- the X coordinate of the LCB and LCG coincide at all trims, but if it is a vessel fixed system -so the water surface moves- then their X values do not coincide for trimmings other than 0 (although physically they are in the same perpendicular to the WL).

Cheers.