This mission is the third of six missions surrounding Ricardo Diaz's drug empire.
Tommy talks to Diaz at his back porch, shooting pigeons with his Shotgun. He talks about wanting a faster boat than his competitors, and tells Tommy of "such a vessel" that has been engineered for one of his Costa Rican rivals down at the Viceport Boatyard. He wants Tommy to go down there and take the boat for Diaz's own.
Head down to the Boatyard, and draw out a good weapon. There are thugs around this area armed with Kruger assault rifles, so be wary of them. You need to get into the warehouse to get to the control panel, in order to drop the boat into the water. Deal with the rest of your enemies, including a couple of dock workers, and drop the boat down.
Some more thugs will flood in, wielding SMGs. You can either pick them off as they charge you, or if you have good Health and Armor at this point, you can make a run to the boat. You will then have to take the boat to Diaz's mansion dock whilst dealing with a 3-Star Wanted Level, which isn't too difficult.
Mission Passed: $4,000
