Conduit

A conduit is a block that gives nearby players the Conduit Power status effect when powered by placing a certain configuration of blocks.

Conduit power
When activated, conduits give the "Conduit Power" effect to all underwater players within 42-96 blocks (similarly to beacons). This effect stops the breath meter from decreasing, gives underwater night vision and increases mining speed. Conduits can be activated in any biome and at any height or depth.

To activate, a conduit needs to be surrounded on all sides by water (either source blocks or flowing water) and the conduit and water must be enclosed in a 5×5×5 frame composed of prismarine, sea lantern, and prismarine brick blocks. Only frame blocks that lie in the same plane as the conduit (i.e. that share an X, Y, or Z coordinate) contribute to activation. A minimum of 16 of these are required and produce an effect range of 42 blocks; each additional block adds around 2.3 blocks to the range (the exact formula is ). The full set of 42 blocks extends the effect range to 96 blocks, and carries the additional advantage of damaging underwater hostile mobs within 8 blocks by every 2 seconds.

Ineffective blocks will not deactivate the conduit if placed as part of the activation frame, and the frame may be further enclosed using any blocks in the corners. However, any blocks placed in the 3x3 area of water within the frame will deactivate the conduit.

Light source
Conduits emit a light level of 15, the brightest possible light level in the game. They emit the same amount of light as glowstone, sea lanterns, jack o'lanterns, redstone lamps and beacons.

Trivia

 * When it is activated, the conduit displays the heart of the sea's texture in the center of its model.
 * An unused texture for the core, an 8x8 version of the Bedrock Edition Heart of the Sea, exists in the Conduit files.
 * Despite the conduit's small appearance, its hitbox takes up a full block.

Gallery
Sauerstoffröhre Conduit