Navigate the depths and scan Bogdan's submarine in this guide for the final setup of Doomsday Heist Act 2.
The 'Submarine Recon' setup mission guide for The Bogdan Problem (Act 2 Doomsday Heist) in GTA Online is the final setup before the Act 2 Finale, utilizing the Strombergs acquired in 'Prep 4a' and Torpedo ECUs from 'Prep 4b'.
This is one of the easiest missions. You and your friend need to get into the Strombergs and head to North Chumash. You need to destroy a convoy here using your Strombergs. You have the option of using either the machine gun or homing missiles. You can switch to your homing missiles and destroy all the vehicles in the convoy which includes both land vehicles as well as the helicopter. The homing missiles will automatically lock on so you don't have to worry about anything — just shoot.