The hitbox of the horse is larger than the hitbox of the boat, making it impossible to break the boat if a horse is riding passenger. You must kill the horse to break the boat.
Linked issues
is duplicated by 15
relates to 4
MC-156814
Horses, donkeys and mules can enter boats as babies and then grow up inside of it, despite their adult variants not being able to enter it
Resolved
MC-13937
You cannot break minecarts with large-sized entities inside of them
Reopened
MC-96212
Horses don't/won't seem to want to go in boats anymore.
Resolved
MC-158330
Polar bears will not get in boats.
Resolved
Attachments
Comments 21
Confirmed on OS X. (15w43c)
Also a "less aggressive" workaround from the lava solution... if a block of water can be placed 3-4 blocks directly above the boat-with-horse, the horse will dismount as the boat is forced under water. Both may then be interacted with as expected.
That's not the problem here, the problem here was that you couldn't interact witha boat if a horse entered it, so they made horses unable to enter to fix that.
If you can't cross a ocean with a horse and boat now, make a bridge, find other means of crossing the ocean.
16w04a / 16w05a: if you get put a horse in a boat (with commands), now you can interact with the boat ... The boat hitbox is below the horse hitbox (you hit the boat down and the horse will disembark)... So, it is not necessary that the horses can not be mounted on the boat 🙂. https://bugs.mojang.com/browse/MC-96536
Heh, like if I'd seen an iPhone... if a feature doesn't work just right, disable it all together. Fixing stuff cost money. Disabling is free! YAY!
The problem of not being able to transport a horse in a boat could be solved by making it so that the Frostwalker enchantment works when riding a horse, in that way you could ride atop a frosted ocean with your horse.
So if I understand correctly, the fix to this problem was to not allow entities with hitboxes larger than that of a boat enter it? So here I was transporting a baby horse in a boat, but now it grew up... What should I make of that? Apparently their hitboxes were tweaked a little allowing us to interact and consequently break boats from underneath. Still not to allow adult horse to enter boats while allowing baby horses in boats to grow into adult size makes no sense to me. And that while it seems like interacting with a boat (while troublesome from underneath) is possible?
So either this bug report or 96212 should be reopened.
migrated
It is possible to get the horse out of the boat by placing blocks underneath and around the boat, removing the water from the enclosure, and then carefully destroying the boat with lava. Not really a practical workaround, but it will do if your favorite horse is stuck.