a vessel's tonnage is indeed a volume (how much can this vessel carry). This international value is now expressed without unit's name.
It was previously expressed in tons or tonneaux (for France). This "ton" is not equivalent to a metric ton which is the weight of 1000 liters of water, but it is equivalent to 100 cubic feet which is around 2.837 cubic meter
Every country's authority has its own calculation for tonnage (from length, beam and inside height).
This is why the tonnage of a Super Maramu is 30.14 in France and is, for instance 33.24 (gross tonnage) and 23.35 (Register tonnage) in UK.
It will for sure be different for Australian or NZ or US flag.
However, Pat's tonnage seems high.
Olivier.
On Wednesday, March 13, 2019, 10:40:10 PM GMT+1, Patrick McAneny via Groups.Io <sailw32@...> wrote:
I should have mentioned that I knew tonnage was not the weight of the boat ,but a volume measurement . Still it seemed high and apparently that is the case and I will have it changed. Thanks for the correct numbers. Pat SM Shenanigans