Tutorials/Endless circling pool

An endless circling pool, also known as an AFK pool, allows the player or any player-sized mob that gets in the water to circle endlessly around the center. These are commonly used for AFK players in multiplayer to avoid getting kicked off the server.

Usage
Endless circling pools, or AFK pools, are primarily used on multiplayer servers. Most servers prevent players from being idle for too long by kicking them off the server after 15 minutes or more. For that reason, some players make "AFK Pools" to prevent being kicked off by the system.

This is why many players build an endless circling pool when they have to be away from the computer. An endless circling pool automatically moves the player continuously. However, it can malfunction once in a while, causing the player to stop moving. Because of this, make sure to check your computer every 15 minutes (or however long the player is allowed to be idle before they get kicked off on that specific server). Also, note that some servers ban the usage of endless circling pools.

Usage notes
Here are some important things to think about when using an endless circling pool.


 * The sound that the water makes may disturb the player, so if you mind the noise, turn the computer's volume off.
 * Sometimes you may stop moving when in an AFK pool, and must manually move the player to start again. Using a second sign as the central block instead of a solid one can prevent this, and makes the pool more reliable.
 * Using an endless circling pool may be against the rules of your server, particularly if it has an auto rank system to give benefits for playing longer, or is often near the player cap. So, make sure to check the rules before constructing one.
 * Using this pool causes your hunger bar to go down, which can kill you in hard difficulty. Riding a boat in a pool wide enough (see below) does not deplete hunger. Otherwise, you keep food on hand for when you return, or make an automatic food farm and keep the  key pressed.
 * The pool should be encased in some sort of building, because otherwise you could be attacked by monsters and die.
 * Keep in mind that, if you are in a multiplayer server, other players might troll you when you are AFK.

Construction


When you are ready to build an endless circling pool, you need only basic materials:
 * Building blocks (such as stone bricks)
 * A sign or button (buttons cost the least to craft)
 * A stair, slab, or pressure plate (the pressure plate costs the least to craft, and creates a smoother transition from the top of the stream from the bottom)
 * A water bucket

The following schematics show the construction of an endless circling pool:


 * Schematic


 * Construction notes
 * You can replace the stone bricks shown in the grids above with any solid block, such as cobblestone or wood planks.
 * The slab can be of any type. It can be any block one automatically steps up onto, that water cannot wash away, meaning that stairs are another option. Place the slab or stair under the water source that is 2 blocks high.
 * The water source block (marked with an S) flows down, and around to under the sign.
 * After the water is flowing correctly, the sign can usually be removed once everything is in place.
 * 1.13 has changed the water flow mechanics, such that the end of the water has less current. This can cause you to get stuck on the central block. Replace it with a sign instead to solve this issue.


 * Layered blueprint

To use the endless circling pool, simply jump into the water at any place in the flow. The water should constantly carry the player using the pool all the way around.

Endless circling moat


A better variation is to build a two-block-wide channel, which can accommodate a boat that you ride in. The advantage is that hunger is not depleted while riding a boat.

With proper water management, one can construct not only circling pools, but also moats around arbitrary areas. Strategic placement of water source blocks along with signs or buttons are used to control the flow of water such that one flow pushes the boat into the next flow, but the next flow pulls the boat out from the previous flow.

Using the techniques described in Tutorials/Water-powered boat transportation, the smallest circling pool that can accommodate a boat has one solid block in the center and four quadrants of water flowing from one corner of each quadrant. This design requires a 7×7 area, 1 layer, 4 water source blocks ("S" in the schematic), and 8 buttons or signs — one on each side of the central block and one on the wall opposite each central sign or button.