As an experienced Minecraft player, I can provide detailed guidance on using Heart of the Sea items to create and activate conduits for enhanced underwater gameplay.
Table of Contents
- What is a Heart of the Sea?
- What Does a Conduit Do in Minecraft?
- How to Craft and Activate a Conduit
- Tips for Using Conduits Effectively
- Things to Build with an Underwater Conduit Base
What is a Heart of the Sea?
The Heart of the Sea is a rare item that generates buried inside chests found from treasure maps, which are found inside chests in ocean ruins and shipwrecks. The main use of the Heart of the Sea is crafting conduits. It cannot be crafted or obtained through trading with villagers.
What Does a Conduit Do in Minecraft?
A conduit is a beacon-like utility block that provides “conduit power” to players in an area around it when placed underwater. Conduit power grants the following effects:
- Water Breathing – Unlimited breath underwater
- Night Vision – Improved underwater visibility
- Haste II – Faster breaking of underwater blocks
Additionally, conduits attack hostile mobs like guardians and drowned within an 8 block radius, making them great for keeping areas around underwater builds safe.
How to Craft and Activate a Conduit
Follow these steps to craft and activate a fully powered conduit:
1. Obtain the Ingredients
You will need:
- 1 Heart of the Sea
- 8 Nautilus Shells
To get a Heart of the Sea:
- Find an ocean ruin or shipwreck
- Look inside chests for a buried treasure map
- Follow the map to the X marks the spot and dig down to find a buried treasure chest containing the Heart of the Sea
To get Nautilus Shells:
- Fish using a fishing rod enchanted with Luck of the Sea III
- Kill drowned zombies holding shells (3-9% chance to drop) 
- Trade with wandering traders (5 shells available per trader) 
2. Craft the Conduit
Place the Heart of the Sea in the middle square of a crafting table and surround it with 8 Nautilus Shells to craft the conduit.
3. Build the Conduit Frame
The conduit needs to be activated by placing it inside a frame of certain blocks around it:
- Dark Prismarine
- Prismarine Bricks
- Sea Lanterns
The more blocks used, the wider the conduit’s area of effect. For the maximum 96 block effect radius, build a 23×23 frame with the conduit in the center so that there are 42 blocks between the conduit and edge of the frame.
4. Activate the Conduit by Placing Underwater
Finally, build the frame with the conduit around it underwater in the desired location. When powered, you will see the Heart of the Sea inside the conduit light up. Go near the conduit while underwater to receive conduit power.
That covers the entire process! Let me know if you have any other questions.
Tips for Using Conduits Effectively
Here are some useful tips:
- Build multiple conduits spaced 96 blocks apart to cover larger underwater areas
- Bring pets underwater by right-clicking them with a Heart of the Sea for conduit power
- Make air pockets inside builds so you can temporarily disable conduit effects
- Use conduits when making underwater farms and mob grinders to quickly kill mobs
- Link nether portals to conduits so you can fast travel to your underwater base
Things to Build with an Underwater Conduit Base
Having an activated conduit opens up many possibilities for underwater bases. Here are some fun builds to try out:
Make a cozy glass-domed house filled with furniture, storage, and amenities. The conduit lets you walk around inside without flooding. Add a nether portal room for fast travel.
Ocean Animal Farm
Breed and harvest fish, turtles, dolphins or guardians. The conduit power will automatically kill most hostile mobs.
Coral Reef Museum
Build biodomes around coral to showcase colorful reef life. Use signs and book stands to provide information.
Use new 1.13 blocks like sea pickles for lighting. Serve pufferfish dishes to friends without poisoning them!
Make an underwater base with a conduit surrounded by guardian statues and prismarine builds. Link to an ocean monument.
The Heart of the Sea conduit provides awesome benefits for underwater survival and building. Find buried treasure, craft the conduit, build an activation frame, and start making your underwater dreams a reality! Let the conduit power up your gameplay.