How to Raid an Ocean Monument in Minecraft

Guide Java Bedrock

Quick answer: Bring water breathing potions, night vision, good armor and milk. Kill the 3 elder guardians (top room and both wings) to stop new Mining Fatigue applications; then clear the remaining effect with milk or wait for it to expire. Loot 8 gold blocks in the treasure chamber and any sponge rooms that generated.

What you need

Water breathing potions
Night vision potions
Milk buckets (Mining Fatigue)
Depth Strider boots and Respiration helmet
Sword or bow, plus food

Step by step

Prepare water breathing potions (extended potions last 8 minutes), night vision, Depth Strider boots, armor, a weapon, food and milk. Doors provide underwater air pockets in Java only; do not rely on that trick in Bedrock.
Elder guardians within 50 blocks apply Mining Fatigue III for 5 minutes. Milk clears the effect, but Java elders check once per minute and Bedrock elders can reapply it immediately while you are in range.
Kill the elder guardian in the top room, then the one in each wing. Break line of sight with solid blocks while its laser charges. Its extended spikes hurt you when you hit it, so watch your health.
Loot the treasure chamber in the central section: 8 blocks of gold encased in dark prismarine.
Look for sponge rooms, which have an opening in the floor and about 30 wet sponges on the ceiling. They are not guaranteed to generate. Killing each elder yourself is another source of wet sponges.
For a guardian farm afterward, use a design for your edition. Bedrock uses 25 fixed spawning columns, so Java and Bedrock layouts are not interchangeable.

Java vs Bedrock

Both editions have three elder guardians per monument. Doors provide underwater air pockets only in Java. Bedrock guardians spawn in 25 fixed columns. Milk can give a brief break from Mining Fatigue in Java, but Bedrock elders can reapply it immediately in range.

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

Frequently asked questions

How do you get rid of Mining Fatigue in an ocean monument?

Kill all 3 elders to prevent new applications, then drink milk or wait for the existing effect to expire. While elders remain alive within 50 blocks, Java checks once per minute and Bedrock can reapply the effect immediately.

What loot is in an ocean monument?

8 gold blocks in the central treasure chamber, prismarine and sea lanterns, and about 30 wet sponges per sponge room if any generated. Killing elders yourself gives wet sponges, a 20% chance for a tide armor trim, and prismarine loot.

Can you drain an ocean monument?

Yes. Use sponges to remove water, then dry them in the Nether or a furnace for reuse. For a guardian farm, follow a design made for your edition rather than assuming draining alone creates a working farm.