You may wish to save ships or transfer them between worlds, and there are a few options to do that.
WorldEdit
To save a ship as a WorldEdit schematic, you must use the wand, which can be acquired with the //wand command. Select two opposite corners of the ship, then run //schematic save insert-name-here to save the schematic. Be sure to select the ship only, not the world around the ship. Do note that you will need to shipify the schematic when you paste it later.
To paste a schematic on a pre-existing ship, run //toggleplace, which will move the schematic’s placement from your character to a position selected by the wand. After that, select the point on your ship, load the schematic, and paste it.
Vmod
Vmod has a system for directly copying ships and unlike the other methods, the ships will be placed in ship form and will have all attached ships like physics bearings intact.
To save a ship, press tab while holding the toolgun and navigate to the schematics section. Exit the menu, and left-click a ship with the toolgun to select it. You can now rotate the schematic with the scroll wheel and right-click to place it. To save the schematic as a file, reopen the toolgun menu, select save, and enter a name.
To load a ship schematic, open the toolgun menu, navigate to the schematics section, and click the load button on the schematic you wish to load. You can now right click to paste it in the world.
Create
To save a ship as a Create Schematic, select two opposite corners of the ship with the schematic and quill item, then right click a third time to save the schematic. You can use Ctrl+Scroll to resize the schematic before saving it. As with WorldEdit, be sure to select the ship, not the world around the ship.
Currently you cannot paste Create Schematics on ships, but that functionality will be added in the future.