This is a map guide split into parts as I didnt want to cram one image full of markers.
I found that splitting up NV into each district was easier.
Legend:

Notes:
- Black and white circle = Guard tower with a Rare Crystal chest inside

-The Red duck is located inside a Safe, the Code is: 74-17-76

Notes:
- The Black duck is located inside of a Safe, the code is: 6-6-6
-The top of the VNC tower is a great place to go to if you want to reach the top of nearby skyscrapers. Just find something to do while the elevator is ascending... Zzzz

Notes:
-The Red duck is located in an office area, inside of a Safe. The code is: 10-28-64

Notes:
-The Black duck is located in the Trunk/ Boot of a sunken police car. You will have to lockpick this. Take a deep breath!
-Why the Devs chose to place the Inhibitor chest so far away from anything important is beyond me. the placement makes ZERO sense. Most people will be missing this chest as it is so far away that you will not get a proximity notification until you are already swimming to it. Grrr!

Notes:
- #1 = Guaranteed Purple Rarity Crystal behind a table and chairs on the Roof of the Metropolitan Art Gallery

- #2 = Small Crystal Chest inside the Guard Tower
-The Red duck is located inside of a GRE container, in a safe. The code is: 10-10-10

Notes:
-The Red duck is located inside of a GRE container, in a safe. The code is: 85-19-45

Notes:
-The Black duck is located on top of a Green Mooring Post near some Chemicals.

Notes:
- The lower Inhibitor of the two marked on the map can only accessed properly once you have beaten the game or reached the Dam in the story. (No spoilers here!)
- The Red duck is located inside of a safe. The Code is: 4-5-9

-The Red duck is inside of a safe within a Nightrunner hideout on the other side of the dam bridge.
The Safe code is: 9-6-6
-The Black duck is located inside of a Guard tower that connects to the walls around the Ruined Observatory.

If I missed any collectibles from my legend please let me know in the comments.
Check out my other Guides for DL2 if you found this one helpful!
Old Villedor Map:
https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=2884520878
Dark Hollow Guide:
https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=2798844622

Thanks for reading!