Doesn't that implicitly depend on what you've fully laden?
Boats are usually weighed in a different manner than their displacement
is calculated. Don't even get started on "Thames measurement". You weigh a boat in the slings, crudely (within 500 pounds, say). You calculate the displacement either by doing a back of the envelope calculation of the volume of the hull
form, or by putting a 12 x 6 x 40 foot hull
into a 15 x 10 x 45 foot box with enough water
to float it...and then seeing how far the water
goes up the wall. Taking a bath is you displacing water in a tub.
Guess what? The displacement is different in fresh and salt water
and warm and cold water. Look up "Plimsoll line
" for further partings of the curtain of mystery, although the short version is that is what all the numbered dashes on the bows of freighters mean: "load to here and no further in these conditions". Weight's not the issue. It's volume and the effects of the water on the buoyancy of the ship. You could tie a truck to the deck
of your Morgan
in the Dead Sea and creep quite cheerfully without decks awash. Try it in the Great Lakes
, and you're an amusing artificial reef.
Boats are often weighed at "empty", "light" and "laden" points. "Empty" is empty tankage and as close to no gear
as is possible. "Light" is, say, half tanks
and "normal" safety gear
, like an inshore or coastal cruiser would have, and "laden" would be "full tanks
, twenty cases of beer
, six month's of food
, all my dive gear, a compressor
, eight 4D batteries, 500 pounds of chain and six anchors."
That's when you get to see if the waterline stripe has any bearing on reality.
Hope this has helped. Like "how long is a piece of rope", it's not a straightforward subject.