I beleive that "tonnage" is not directly related to displacement but
rather the internal volume of the boat that is usable to carry cargo.
Something like that. Anyway, the tonnage of my boat is quite a bit different
than the displacement.

The OP started the post by referring to weight (displacement), but the
final question seemed to be more related to the width of the trailered
boat.

Doug
s/v Callista

"DUINK" wrote in message
...
As far as I know displacement = weight. Certainly the weight of the boat
will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard
refers to
a tonnage (don't recall if they call it displacement) that relates only to
boat
volume, not the weight.