Java Edition 18w07a

18w07a is the eighteenth snapshot released for 1.13. It is the first to be released after the decision was made to include the Update Aquatic features in 1.13, and as such contains more gameplay additions than the previous snapshots for 1.13.

Blocks

 * Added stripped logs, a smoother log variant.
 * Created by right clicking with an axe on a log.
 * Act as regular logs, and can still be used to craft planks.
 * Added bubble columns.
 * Created by magma blocks or soul sand in water at least 2 blocks deep.
 * Magma blocks columns push entities down: they will stop items from floating up in water and sink boats.
 * Soul sand columns push entities up.
 * Added kelp blocks as well as seagrass which were called "Sea grass" at the time
 * Can only be placed underwater, requiring at least one water block above it.
 * Can be placed on dry land by using the command.
 * Generate in oceans.
 * Can grow multiple blocks high.
 * Have animated textures.
 * Sea grass also comes in a tall variant.
 * Sea grass can be generated when right clicking any block underwater.
 * Kelp can be smelted into dry kelp.
 * Added dried kelp blocks.
 * Smelts 20 items when used as fuel in a furnace.
 * Added prismarine stairs and slabs.
 * Added turtle eggs
 * Stepping on turtle eggs will break them.
 * Zombies and zombie pigmen will intentionally step on turtle eggs.

Items

 * Added new trident weapon.
 * Can be thrown by it, or be used as a melee weapon by, dealing  damage.
 * Are currently unobtainable in Survival Mode
 * Added kelp and dried kelp.
 * Kelp can be used to place a kelp plant underwater.
 * Kelp can be dried in a furnace to create dried kelp.
 * Dried kelp can be eaten, restoring hunger point.
 * Added turtle shell pieces.
 * Dropped when baby turtles grow up.
 * Can be used to craft turtle shells.
 * Added turtle shells.
 * Can be used as a helmet, adding 2 armor points.
 * While equipped and out of water, it will give the player the Water Breathing effect for 10 seconds, essentially giving the player 10 extra seconds of breath underwater.
 * Can be used to brew the potion of the Turtle Master from an awkward potion.
 * Added potion of the Turtle Master.
 * Will give Slowness IV and Resistance IV for 1 minute.
 * Brewing it with redstone dust will extend the effect time to 3 minutes.
 * Brewing it with glowstone dust will increase the effect amplifiers from IV to VI.
 * Brewing it with gunpowder or dragon's breath will create a splash or lingering potion, respectively.
 * Added arrow of the Turtle Master.
 * Added turtle spawn eggs
 * Added phantom spawn eggs

Mobs

 * Added phantoms.
 * Spawn in the Overworld and the End, sometimes in groups of up to four.
 * Attack players who haven't slept in a while.
 * Drops 1-4 leathers.
 * This may change.
 * Added turtles.
 * Spawns on warm beaches (in plains, jungles, swamps, deserts, mesas and savannahs), in groups of 1-5. This is temporary.
 * Will lay eggs in their home beach.
 * Drops 0-2 sea grass upon death.
 * Drops 0-1 bowl when killed with a trident enchanted with Channeling.
 * Can be bred using cod. (later changed to sea grass)
 * You can craft pieces of their old shell into one big shell.
 * Added tridents.

Gameplay

 * Enchantments
 * Added Loyalty.
 * Goes up to level III.
 * Used on tridents to make it return when thrown.
 * Added Impaling.
 * Goes up to level V.
 * Used on tridents to deal more damage to sea creatures.
 * Added Riptide.
 * Goes up to level III.
 * Used on tridents to launch the player when thrown while in water or rain.
 * Added Channeling.
 * Only has one level.
 * Used on tridents to summon a lightning bolt on impact with a mob during storms.
 * Requires the target mob to be directly under an open sky and in a biome where it is raining.


 * Movement
 * When sprinting while swimming, the player will now go much faster than normal swimming, and rapidly dive down to the lowest point in the body of water.
 * The player's hitbox is only as large as 0.6×0.6 blocks (same as while flying with an elytra) while doing this
 * Vertically, the player can fit through a one block gap like this
 * If the ceiling block is solid, movement is very slow while in such a small space, for any other ceiling block like a bottom slab movement speed is as normal

General

 * Added the,  ,  , and   particles.
 * Added the,  ,  ,  ,  ,  , and   NBT tags for turtles.
 * Added the,  ,  , and   NBT tags for phantoms.
 * Added the  statistic.
 * Used by phantoms.
 * Reset when the player leaves their bed.
 * Added the,  , and   block tags.
 * Blocks in the  tag will render in water as if any non-filled space in the block model was water.
 * Added the,  ,  ,  ,  , and   block and item tags.

Mobs

 * Squids now shoot ink in response to being attacked.
 * Zombies, skeletons, ocelots and wolves will naturally attack baby turtles, and zombies and zombie pigmen will seek out and trample turtle eggs.

Non-mob entities

 * Items in water now float up.

World generation

 * In the Nether, vertical air cavities — stretching from bedrock level to as far as Y=35, and filled with lava from bedrock level to Y=10 – now occur in chains across the bottom of the Nether, often forming extensive ravines.

Video
Video made by slicedlime: