From the introduction:
A captain bellows orders to his crew as they struggle to control the sails against the storm winds. Tacking slowly through a harbour a brig draws fascinated stares from children playing. Rocking violently a 3rd-rate fully rigged ship fires it’s second broadside and its crew cheers as the first of the enemy’s ships begins to take on water.
Many worlds rely on naval transport for everything from trading to warfare. Early in the career of adventurers any interaction with these marvels of engineering is likely to be limited to a few bartered passages aboard merchant vessels. Later in a campaign, players may wish to procure their own ship to stop paying other characters to travel, or even to use as a mobile base of operations.
Much like a castle or fiefdom bequeathed to or bought by the players, a ship owned by the players provides ample opportunity to roleplaying and new quests centred around the development or protection of their property. Unlike a more permanent stronghold, a ship allows the players to easily change their focus and accept quests located further afield. A solid investment for any adventuring party, ships are one of the best ways for them to transition from local nobodies to national heroes.