How to Get Aqua Affinity in Minecraft

Guide Java Bedrock

Quick answer: Aqua Affinity removes the 5x mining-speed penalty from having your head underwater - one level on a helmet or turtle shell. The separate 5x floating penalty still applies, so stand on solid ground underwater to mine at full speed. Get it from enchanting tables, librarian trades, fishing, or structure and trial chamber vault loot.

What you need

A helmet (or turtle shell)
Enchanting table + bookshelves
Librarian + lectern for the book
No anvil chain needed - max level I

Step by step

Enchant a helmet: Aqua Affinity rolls on enchanting tables for helmets. It's max level I - one lucky roll and you're done, no anvil combining needed.
Trade with librarians: reroll a lectern until an Aqua Affinity book appears and lock it. Since it's single-level, the cheapest trade is all you need.
Fish and loot: fishing books and chests in desert pyramids, strongholds, ocean ruins, ancient cities, mansions, pillager outposts, mineshafts, monster rooms and jungle pyramids carry it - plus vaults in trial chambers. Bedrock raid mobs drop books too.
Know what it fixes: mining with your head underwater normally takes 5 times longer. Aqua Affinity grants +400% submerged mining speed, canceling the penalty completely.
Know what it does NOT fix: floating (not touching the ground) has its own separate 5x mining penalty, and Aqua Affinity does not touch it. Without Aqua Affinity, underwater plus floating means 25x slower; with Aqua Affinity while floating it is still 5x. Stand on the seafloor or any block to work at full speed.
Apply it to a turtle shell too: shells accept Aqua Affinity, so your water-breathing helmet can also be your underwater mining helmet.
Build the ocean kit: Aqua Affinity (mining) + Respiration (air) on the helmet, Depth Strider on boots, and a conduit nearby for long projects.

Java vs Bedrock

Identical effect in Java and Bedrock at level I: the 5x underwater penalty is gone. Only difference: in Java, command-only levels above I add another +400% submerged mining speed each; in Bedrock extra levels change nothing. Bedrock also gets books from raid mobs.

Versions: Describes the current Java and Bedrock releases. See the edition note for differences.

Frequently asked questions

What does Aqua Affinity do?

It removes the 5x mining-speed penalty for having your head underwater, so you break blocks at normal speed while submerged. It does NOT remove the separate 5x penalty for floating - stand on solid ground underwater for full speed.

Is there Aqua Affinity 2?

Not in Survival - the maximum level is I. In Java, commands can apply higher levels that add +400% submerged mining speed each, but Bedrock gains nothing from extra levels.

Aqua Affinity vs Respiration - which should I get first?

Get both on the same helmet - they stack and cover different needs. If you must pick one: Respiration first for survival (more air), Aqua Affinity when you start serious underwater mining or building.