The Hermetic Shipwright
There are three options for constructing the ship prior to enchantment. The first and most straight-forward way of constructing a ship is to rely on mundane skill and labor. A skilled shipwright, leading a team of around 10 craftsmen and laborers, can finish a ship in two seasons. This is based on a shipwright with a score of 5 in the Profession: Shipwright ability. This decreases to a single season when the shipwright gains a score of 10 in the ability. See City & Guild, page 68, for further detail.
The second option is to use Rego craft magic (Covenants, page 49) to process and assemble the parts of the ship. This approach requires a high Finesse ability, but can reduce the time taken to build a ship. Liberal use of craft magic, to process smaller components, can double the efficiency of the shipwright, effectively halving the time it takes to build a ship.
The third option is to use Creo rituals to conjure the ship. This is clearly the fastest way of "building" a vessel, but again relies upon Finesse and the expenditure of vis.