What's the easiest or quickest way to build bases under water? Stopping every 15 seconds for air is becoming very infuriating. Are there mods or something I can do to speed up the process or even just perhaps allowing me to stay under water longer?

At the moment, I build a grid of how many blocks I desire, then do a one-block tower in a zip pattern and level to the height of the grid, and then put a ladder on each of the blocks which removes the water block.

7 Answers 7


Actually there are some awesome tricks I used to build Atlantis on my server--they all stem from the fact that water cannot occupy the same square as anything else.

First of all bring a door with you. When you are down there, set it on the ground, open it and step in. You will be in an air bubble. This can be done any time to catch your breath and it's not a bad way to escape from monsters at night.

Secondly signs, ladders, fence-posts all resist water and can be used as blockers. I played with all these for a while:

Signs aren't stackable, you spend all day running back and forth building them.

Fence-posts block you so you can't just swim up and down, overall they will work but are unwieldy.

The best solution I found was ladders--but place them ABOVE your head. You can still jump up and down through them, but if they are at your level you will climb up them every time you move--it's really frustrating (This is no longer true in the latest version making ladders the clear winner).

There is a pattern where you have one block above you with ladders on each side, the a "Knights move" to the next block with ladders on each side. It makes a good roof with no more blocks than you need.

If you want the water to be right over your head in some areas, use signs.

The knights move I was referring to is the L shaped move they make in chess. You can make a ceiling of blocks like this:

 . . . . * . . . .
 . * . . . . * . .
 . . . * . . . . *
 * . . . . * . . .
 . . * . . . . * .
 . . . . * . . . .

Where the "*" are blocks and the "." are empty space. Note that in this pattern, each "." is adjacent to a * (and therefore are actually filled with a ladder attached to the *).

  • 1
    I really like the door/air bubble trick, that'll be handy. By "Nights move" were you referring to the L shaped move of a knight in chess? If you have a link to some screenshots it might help make things more clear.
    – Fambida
    Commented Apr 11, 2011 at 6:19
  • With two or three doors you'd be able to "walk" them with you. Sounds fun.
    – Kzqai
    Commented Apr 12, 2011 at 16:43
  • 1
    When I first figured the trick out I placed doors strategically about 10 blocks apart under water so I could walk from one to the next to cross the ocean. You only need the occasional breath. Works much better if you have jack-o-lanters or gold bricks to place next to the doors for light. It's possible to use torches and a strategic placement of glass as well but harder.
    – Bill K
    Commented Apr 12, 2011 at 17:57
  • 1
    In 1.5, ladders at head-height can no longer be climbed without jumping, so the problem of accidentally climbing when trying to move around is gone. Commented Apr 29, 2011 at 20:12
  • Yep, been thinking of lowering the roof in atlantis by one square now :)
    – Bill K
    Commented Apr 29, 2011 at 20:37

What I do is to build a walkway over the water and use it to drop sand to fill the area I want to be air. I then build the walls and ceiling around the sand before digging out the sand from below. Afterwards remove the walkway if you want to and you're done.

  • doh why didn't I think of that lol. I'll see what others say before I accept any answers, but thats an awesome idea thanks!
    – Jared
    Commented Apr 11, 2011 at 0:19

You can also use sugar cane to breathe under water. Note, that you need to place the sugar cane next to a "hole" with water.

So i usually dig two blocks, fill one up with dirt, and place two sugar cane's on top of the dirt. Now you can stand inside the sugar cane blocks and take a breath ;)

Btw, if you dig, shovel, etc. while standing inside the sugar cane blocks, you're working as fast, as if you were standing on land ...

  • 1
    That's a good idea, sugar cane breaks much faster than ladders and doors.
    – Sadly Not
    Commented Apr 11, 2011 at 14:12
  • 8
    Crafting idea - sugar cane snorkel :) Commented Apr 12, 2011 at 15:48

Sign Ceilings

@Bill K mentioned signs and has a good point that they're not stackable, but they're still a very viable option.

Signs can now be stacked to 16.

The trick for signs is that you only need to make 1 before you go underwater. Carry stacks of raw wood with you when you go under, and you'll be able to mass-produce signs while underwater.

This gives you the ability to make open ceilings of any size, as signs (currently†) can be placed on other signs.

When you go under you'll want to bring the following:

  1. SCUBA item – any item that can be used for temporary breathing (door, ladder, sign, etc)
  2. Stacks of wood
  3. pickaxes
  4. shovels
  5. torches/coal

Swim out to where you want to build underwater, and drop to the bottom. If it's very flat, you may want to bring a door so that you have a pocket of air at your head. the pocket of air needs to be at your head, not your feet.

Place a workbench right next to the air pocket, and build a bunch of signs. I usually do 8 at a time. You may want to build a storage box to hold extra supplies/wood so that you can carry more signs. Place one sign on a block, and continue extending that line of signs to whatever length you'd like. Each row of signs will need an "anchor" block to be attached to. Choose your anchor blocks carefully, as all the signs chained to that anchor will fall if the anchor is moved/broken. Gravel, sand, and dirt do not make particularly good anchor blocks. Glass can look nice, but it's easily broken, so be very careful.

Make sure you have one space below the ceiling as you work so that you can keep your head within the air pocket while you're moving about. It's a good idea to put torches on the block below the anchor block to identify them and give some light to work in.

Once you've built your ceiling you can dig as far down as you'd like, but be careful as the signs will not give you anything to hold onto, and you may be damaged if/when you fall through. Having a secondary ceiling of glass can give you something to land on without risk of injury. Also it can provide a platform to jump off of to get back in the water:

~~~~~~~   ~ - water
======A   = - sign
      #   A - anchor
:::::H#   # - block
     H#   : - glass
     H#   H - ladder

† This same trick can allow you to create floating ponds and canals, but it's my understanding that this was an unexpected "feature" (read: bug) which may or may not be "fixed" in future updates.

  • Not really seeing how signs are an advantage over ladders, which stack. And if you only start with one sign, you have to make a workbench in the area, which is another step that ladders don't require.
    – Cyclops
    Commented Apr 11, 2011 at 21:33
  • @Cyclops, if you're building underground, you're bound to build a workbench either way. Signs allow you to have a fully open "roof" without any blocks getting in your way. I am in no way saying that ladders are bad, but as @Bill K had already talked about ladders, I felt that signs could use some representation on the list.
    – zzzzBov
    Commented Apr 11, 2011 at 21:39
  • That's a nice way to go. I'm thinking of playing with it, but I already go through a LOT of wood with the ladders, I can't imagine how much I'd burn through with signs. I was building 4 stacks of 64 ladders at a time, with signs it would be a lot more time building, but probably worth it for a smaller area.
    – Bill K
    Commented Apr 16, 2011 at 3:28

If fire spread is enabled get some shears and harvest jungle leaves, build your structure solid out of them, then place a layer of glass above and use flint and steel to light it. The leaves will be gone in seconds leaving a dome of glass holding the water back. I've used this for underwater domes up to 50 blocks across.


I've found the easiest way is to create a pillar of sand/gravel (gravel recommended, because I assume you want to save the sand for glass, but maybe you have enough sand) then place ladders on each side of these blocks. You then move in Bill K's method, moving a Knight's L move away for the next tower.

  • Don't forget: the bottom of an ocean is often sand, so sand can be easily obtained.
    – user28379
    Commented Nov 6, 2012 at 20:14

One word: /fill. 😜

First, you should /fill the ceiling of your base. Usage:

/fill X1 Y1 Z1 X2 Y2 Z2 minecraft:(the block you want for the ceiling.)

Next, create walls! Use the same command format.

Lastly, clear out a space under it using minecraft:air as your block ID.

Have fun!

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