I’ve just swam across the docks, dodging bullets from the helicopter. I’m trying to find a lab of some sort. All the doors have red locks on them (but aren’t colored red in the map)—it’s colored purple on the map.

I haven’t picked up any passcode cards in the beginning maps because I figured I’d have to go back since there are all these doors I can’t open yet.

I figured maybe I missed something, but when I swim all the way back, I can’t mantle up just past the docks to the left.

Can anyone give me a small hint of what to do? Just a nudge.