Question:

My vessel model has a sunken poop deck on the aft sections while a sponson
that wraps the hull remains at the original deck height.  How can I specify
the margin line to follow the deck edge and not the sponson?



Answer:


If you want to lower the margin line in way of the sunken poop, you could put
deck-edge markings on the shape of hull.c starting at 129.57.  Then you could
leave your sponson marked and use a uniform 3" margin for both.

You can do this with Model Converter as follows:

 MC testml.gf (hull\hull.c) fixup /deckedge: 129.57, 141.98 /margin:0.25
 MC testml.gf (hull\sponson.c) fixup /margin: 0.25

Then to get a full report on the freeboards and margins in any condition, try

  STATUS FREEBOARD:ALL

This will show freeboards to deck edge as well as the margin values.  It
includes every deck-edge point, listing them component-by-component.  So you
will first see the hull freeboards in way of the poop, then the sponson
freeboards.