In my town of Costa Azul on the LilacMC Minecraft Server, we have a nice little fishing area, which is great because there are 10-minute long fishing competitions every hour on the hour. I decided it would be neat to have a conduit floating underneath the docks since they give light, allow you to breathe underwater, and can help with those pesky undead that float over sometimes. A conduit is made with one Heart of the Sea and 8 nautilus shells. You also need prismarine blocks to form an interesting shape around it. The video shows how it changes when the shape is complete, and the sound it makes is really cool. Check out the LilacMC server!