If you need to breathe underwater in minecraft, perhaps because you’re building underwater or because you’re trying to play on a map or server which has underwater objects hidden far below, then you need to know how to breathe in water in minecraft. It can be done without the need for any cheats or mods.
Underwater Breathing Tip #1: The Iron Lung
If you’re descending very great depths and there’s no way of placing any blocks, then having a bucket on hand and right clicking it will create a temporary air pocket which will replenish your oxygen. Basically, iron bucket = unlimited minecraft waterbreathing.
Underwater Breathing Tip #2: Placement Is Everything
Sugar cane can be grown on the ocean floor and used to create a vertical shaft of air going as high as you care to build it. Remember, to plant sugar cane underwater you will need to place it ‘next to water’ this effectively means having a lower ground level next to the place you plan to plant your cane. You won’t be able to place it on a flat sea floor, you’ll need to dig a hole next to it first
Sugarcane is probably the best undersea oxygen station, but doors will also work well for creating a 2×1 underwater air pocket. Other placable air pocket objects include ladders (useful if you’re travelling down a sea wall) signs and trapdoors.
Underwater Breathing Tip #3: When All Else Fails, Try Magic!
Respiration enchantments can be applied to helmets. A respration enchantment adds fifteen seconds to the time you can spend underwater with every level of the enchantment, to a maximum of an extra 45 seconds, also draws out drowning time by one second per tick, slowing suffocation and drowning by a considerable amount.