With all due repect to TJalfur, I think that it is a huge mistake to say that "the most important feature of a ship sailing in the ocean is weight." In and of itself, weight does nothing good for a boat; In and of itself weight does not add strength, it does not add seaworthiness, it does not add carrying capacity, it does not add seaworthiness, it just adds higher stresses and makes a boat harder to handle.
While it is important to have adequate displacement to be able to carry the gear, consumables, and spares to make passages,and to have adequate structural strength and adequate ballasting to stand up to its rig, any weight beyond that is detrimental to the boats prime mission which from my perspective is to sail efficiently.
Traditionally the rule of thumb has been cited as roughly 2 1/2 to 5 long tons of displacement per person. These days that number has crept up as we have become increasing dependent on more sophisticated equipment to operate our boats. Ideally, from a motion comfort, seaworthiness and motion comfort standpoint, that weight should be spread over as long a waterline length as is practical and still achieve adequate structural and ballasting capacities.
Then it comes down to hull shape.