You should be able to go down to the Coast Gaurd station and find some of this out.
If your co. is looking at using one, the owners of the transport know what they haul both in weight and volume
If it is a new one, the mfg can give you a exact capacity
but looking at empy to full weight ?? to many unkowns
like how much ballast they use ? just to mess up things!
SBI
Central Ne.,USA