In the sewers, get past the small pipe jumping puzzle to the blue security beams. Sewer access is through a grate between the two guard stations where the mission begins.

Get past the two sets of blue security beams found in the above tip.

Continue in the sewers past the blue security beams to the room with two barrels emitting toxic fumes. On the other side is a large grate. Just get to it to earn the points. Watch out for the LAM on the other side of the grate.

Get past the large grate mentioned above. This particular grate leads to the underwater method of getting aboard the PCS Wall Cloud.

"Open" the steel hatch that connects Ammunition Storage with the Warehouse north of the main gate. If you open and close the hatch while standing near it the 30 points will be awarded indefinitely.

Open the keypad door in the computer room inside the warehouse north of the main gate.

Same computer room as mentioned above but open the locked door leading to the small storage room.

Enter the locked office in the Base Commander office.

Enter ammunition bay 3 inside Ammunition Storage.

Get past the steel fence southwest of Ammunition Storage and west the Base Commander office.

"Open" the air conditioner vent atop the Naval Assembly Building. Accessible by using the life inside the crane on the northwest end of the yard.

Open all three ammunition bays inside the Ammunition Storage building. Climb atop the ammunition bays heading east. When you hit the last bay these points are earned for having discovered a second way of reaching the catwalk on the east wall.

If you entered through the roof of the Naval Assembly building you'll run into a very large fan. Climb down the ladder and enter the duct behind the ladder through the grate.

Also within the giant fan mentioned above, leave the ladder and enter the door to the northwest. Cross the midpoint of this strange passage to earn the points and some damage.

Thanks to the following agents for their contributions: Krusader for deciding that getting 30 skill points when opening a door just isn't enough.