The Unsinkable expansion for Embarcadero introduces three all-new gameplay modules and has everything you need to add a fifth player. The individual modules can be mixed and matched in any combination.
Unsinkable Ships module: This module adds unsinkable ships to the game. These new ships provide special benefits when docked. But your benefits come at a cost because those ships cannot be sunk.
Entrepreneur Buildings module: The module adds entrepreneur buildings to the game. These new buildings each count as two different card types! They also provide all-new building bonuses.
Events module: This module adds events to the game. These events, which occur twice per game, change the game in various ways, with unique bonuses or decisions for the players to make.
-description from publisher