Does the GLM become obsolete when the vessel is modified?
Generally, if the Trim and Stability book is modified, the GLM
will also need to be updated by a naval architect. For example,
a change in the light-ship weight requires that the T&S book
as well as the GLM be updated.
If known weights are added or removed from the vessel at known locations,
these can be treated as fixed weight items (either positive or negative)
without invalidating the GLM calculations.
Creative Systems, Inc.