Search the following locations to find the plans for the corresponding ship upgrade.

Elite ship	Location
Elite Broadside Cannons	The Blue Hole (coordinates 471, 170)
Elite Fire Barrel Storage	Isla Providencia (coordinates 502, 44)
Elite Fire Barrels	San Juan (coordinates 479, 487)
Elite Harpoon	Andreas Island (coordinates 579, 720)
Elite Heavy Shot	Petite Cavern (coordinates 901, 263)
Elite Hull	San Ignacio (coordinates 379, 770)
Elite Ram	La Concepcion Shipwreck (coordinates 181, 296)
Elite Round Shot	Kabah Ruins (coordinates 769, 145)
Elite Swivel Guns	Devil's Eye Cave (coordinates 488, 353)