Why does my obsidian boat sink?

So I played the new Minecraft snapshot 15w14a, and I saw a obsidian boat in my creative inventory. I put it in the water, but it sank immediately.

Best Answer

Because it is an April Fool's joke.

Boats now sink when underwater, or within flowing water of any depth.

The obsidian boat was a joke boat variant released in an April Fools' joke version.

After realiasing you were talking about the base game not the FORGE-Mod I found this Article.

When checking all the content I am sure it is an April Fool's Day post.

We have removed the ability to directly harm other creatures. You should be rewarded for helping, not hurting.

Seems pretty clear to me.

Because it's made out of obsidian...? per chance?

can't imagine that's the most buoyant element in the Minecraft world

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