It's a good moment to eliminate the hostile sniper (M2.1). Moving from your starting point, head east. You will see a tower in the distance, and a bright light of a scoop. If it flashes and you hear a sound, you need to be careful - the sniper may know your position.
In order to eliminate him, get to the hill above the cave (M2.3), located 50 meters away. From there you should be able to shoot him with or without suppressed ammo.
You need to watch out for the boat that can detect you and kill in a matter of moments. There is an easy way to eliminate it (even with a pistol) - shoot the red containers on its back (you will receive additional 600 XP).
Now, you need to retrieve the report from the fallen body (M2.1). The easiest way to do that is to head for the cave below (two soldiers inside) and run across the beach till you reach the tower - there is a hidden climbing entrance.
Unfortunately, it's not that easy to cross the beach without being detected. Fire at the blue truck (M2.4) using Suppressed ammo - you can lure enemies there by throwing rocks. You will have a lot of time before enemies get back to their position.
Climb up, get to the upper floor of the tower and lean out of the window - use the use the plank and the chain to reach the sniper's position and collect the documents. Your way back won't be an easy one as well (if you want to use the beach again) - it's best to use the bridge (there are two more soldiers) or stick to the east boarder of the map and head north.