This guide is going to teach you how to make a Underwater Base on Unturned. It is a small design that can be expanded if you want to expand it. This is my first guide so far, so please rate up if you like the guide!

(I use metal for this base as it is the most secure, but you can use any material that you have)
You Will Need...
9 Floors
8 Roofs
1 Generator (Minimum)
1 Hole
1 Hatch
16 Pillars
12 Walls (You can also add windows if you want to)
1 Ladder
1 Oil Derrick
1 Oxygenator
(Plus Fuel as Well for the generator)

Step -1. As you can see from the screenshot I am building my base in the bottom Right hand corner of PEI near Tignish Farm.
Step 1. Place Down the 9 Floors in a 3x3 Pattern on the bottom of any body of water.
Step 2. Place Down the 16 Pillars in the corners of each of the floors.

Step 3. Place Down the 12 Walls (or Window) (This house doesn't have walls in the middle, just on the outside).

Step 4. Place down the 8 Roofs on the top and the Hole (It doesn't matter where the hole is).

Step 5. Place down the Hatch in the Hole.

Step 6. Go inside your newly created house and place down the Generator and the Oxygenator. Then put fuel inside the Oxygenator to start it working! It will fill up your white bar at the bottom if it is on.

Step 7. Place the ladder by the hole so that you can get out of the house.

Step 8. Head back outside and place the Oil Derrick outside (the Oil Derrick isn't mandatory, but it will allow you to get more fuel easily).

Step 9. Customize your base with Crates, Lockers, etc.

Step 10. Enjoy your secret base! :D

If you liked the guide please rate up! This is my first guide so I hope you liked it!
I might make another guide for a custom makeshift vehicle. if you liked this guide please say if I should make more!