to unlock you have to finish the mission with diaz the first mission on that 2nd island is the fastest boat around no.15 or 16 in missions
unlock it
you can do things
other citis unlock passworld
012435
in the desert, you have to unlock it
complete the missions
pass the first mission
You cant
no.
when you get to it
You unlock it later on in the game as a mission.
beat some missions and then u will unlock 1 by 1