[MC-93080] Boats appear to sink into some blocks when placed

The bug

When placing a boat on blocks whose outline boxes are taller than their collision boxes (such as soul sand, snow layers, and honey blocks), the boat is spawned on the top of the outline box and falls down to the collision box. This is unlike spawn eggs, which spawn mobs directly on the collision box.

To reproduce

Place a block that has different outline and collision heights (such as soul sand, snow layers or honey blocks)
Place a boat on top of the block
❌ The boat appears to sink into the block.

Linked issues

relates to 1

MC-199048 Z-fighting in boats next to blocks with a certain height difference Reopened

Attachments

MC-93080.mp4

Comments 25

An_yMiner 2015-11-21T04:44:19Z

same on snow layers and half slabs
z-fighting with chest, water

An_yMiner 2015-11-21T04:49:39Z

related to [MC-92555]

Steven W.d.V. 2015-11-21T17:19:26Z

@@unknown I don't think it's really related to that. This issue has more to do with the boat that shouldn't go down.

Steven W.d.V. 2016-02-18T18:28:17Z

Not sure whether to call this fixed or not. The block isn't visible anymore (due to other changes), but the boat still sinks into the block. Also, the repeater is still visible. (1.9-pre1 and 1.9-pre2).

bemoty 2017-08-13T20:15:20Z

Can confirm for MC 1.12.1.

15 more comments

marcono1234 2018-02-05T15:21:30Z

Is this issue describing the same bug like MC-101334?

Steven W.d.V. 2018-02-06T16:07:58Z

@@unknown No this one concerns vertical collision and is not about the size of the collision box.

TheGabro 2020-06-04T13:16:11Z

affects 20w22a

Conem 2020-06-15T13:00:33Z

Confirmed in 1.16-pre5. However, soulsand and snow layers are no longer visible on the surface of the boat (repeaters and comparators still are) - see this screenshot.

Sonicwave 2020-09-12T22:32:40Z

I made some clarifications to the report; the "sinking" behavior appears to be caused by the boat being spawned too high, rather than sinking into the block more than other entities would (as can be seen if you show hitboxes and spawn a boat and creeper on top of honey blocks). I've also removed the part about repeaters since boats don't/no longer sink into them.