Take miniguns to mission | Chapter 5 - Heavy Equipment DI Riptide Guide
Last update: 11 May 2016
Search an inside of the chopper where you find for example med-kit. Then approach one of miniguns and press an Action key to take it.
Then head south, returning to the beach from where you've begun. Approach the boat and put a minigun on it. Return to the chopper and repeat it for the second minigun.
Enter the boat and head south. When you get nearby Santa Maria Mission, eliminate the Floaters. Now start placing the miniguns. I recommend first one at a floor in the northern part of ruins (screen above) from where you can see two main entrances.
Now return for the second minigun. Leave it on the higher level of ruins, so it opens at area on south from mission (screen above). Setting up miniguns ends this quest. Attention: don't forget to talk with Sam Hardy for a reward, which is a Maul.
Main quest unlocked: Stalwart Defence (quest is automatically unlocked after finishing the described mission).