Currently in GTA Online, one of the best methods to earn money is to carry out the robberies of Cayo Perico. This particular heist came with the Cayo Perico update, which is considered one of the biggest and most impactful in the nearly decade-long history of GTA Online. Aside from all the new content, players can take part in the various missions that come with the heist. The most attractive aspect of these missions, aside from the potential winnings, is that players can choose any method to complete them. However, the basis for completing these missions is unlocking the Kosatka submarine.
The Kosatka was the first submarine introduced in GTA Online and remains the only one that players can purchase. It is used as a base of operations for the Cayo Perico missions, but can also be used as the players see fit. That means when players aren’t planning heists, they can take the submarine through the waters surrounding Los Santos.