How to Make and Use a Conduit in Minecraft

Guide Java Bedrock

Quick answer: Craft a conduit with 1 Heart of the Sea (from buried treasure) and 8 nautilus shells, then surround it underwater with 16-42 prismarine, sea lantern or dark prismarine blocks in a cage frame: it grants Conduit Power (water breathing, night vision and haste underwater) in a radius up to 96 blocks and damages hostile mobs.

What you need

1 Heart of the Sea (buried treasure)
8 nautilus shells
16-42 prismarine / sea lantern / dark prismarine blocks
Everything underwater

Step by step

Find a Heart of the Sea: every buried treasure chest (located with a treasure map from shipwrecks and ocean ruins) contains exactly one.
Collect 8 nautilus shells: fishing, drowned drops, or buying from wandering traders.
Craft the conduit: Heart of the Sea in the center, nautilus shells filling the other 8 slots.
Gather prismarine: raid an Ocean Monument (guardians drop prismarine shards and crystals; the monument itself is prismarine) or trade with masons. Sea lanterns and dark prismarine also count as frame blocks.
Build the activation frame underwater: the classic design is three 5x5 open squares (like a cage) centered on the conduit, using 42 blocks for full power. A minimum of 16 blocks in any valid ring pattern activates it at reduced range.
Place the conduit in the center, fully waterlogged. It activates with a glowing eye when the frame is complete.
Enjoy Conduit Power in the radius: infinite water breathing, underwater night vision and faster mining - 32 blocks at minimum frame up to 96 blocks with all 42.
Fully powered (42 blocks), the conduit also zaps hostile mobs (drowned, guardians) that come within 8 blocks of it in water or rain.

Java vs Bedrock

Identical in Java and Bedrock: same recipe, frame requirements and effect range. The conduit's hostile-mob attack also works in both editions when fully framed.

Versions: Conduits were added in 1.13 (Update Aquatic). Unchanged in current versions (26.3).

Frequently asked questions

Where do you find a Heart of the Sea?

In buried treasure chests - always exactly one per chest. Get treasure maps from shipwreck map chests or ocean ruins, then dig at the red X.

How big is the conduit range?

32 blocks with the minimum 16-block frame, scaling up to 96 blocks with the full 42-block cage.

Do conduits work out of water?

The conduit block must be waterlogged (or rained on) to function, and its effects only apply to players touching water or rain.