Mesh for hydrostatic pressure

Hello,

 

I have to apply hydrstatic pressure onto the lower part of my model. See attached picture. (this is a barge within the water)

 

-Should I model 2 different blocks? And then mesh both, and apply pressure > equation > hydrostatic pressure?

-Should I model 1 solid block and then split the mesh somehow?

-Should I model 1 solid block and am I able to select nodes/elements up until the waterline?

 

Thanks in advance.

 

Best regards,

 

Joep

 

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