I'm not sure if this is intended behavior or perhaps a side effect of one of our plugins, but certain structure generation seems to be "off" in newer mining world resets. An example can be seen here in Main East's mining world at X: 3181 Y: 51 Z: 3889 where a sunken ship is off by 1 layer and the torn half is made out of completely different wood materials. It's also worth noting the ship is along a chunk border. Again I'm not sure if this is a side effect or intentional behavior. It could just be Minecraft being Minecraft, or perhaps something to do with shadow seeds. Figured I'd post this here since it doesn't seem natural.
I don't do much with mc internals so I never thought much of it, but I have been seeing this behavior for some time both vertically and horizontally. Even buildings embedded in the ground where I have to mine the blocks around them.
Ah, was looking into this bug a while back, it's just a vanilla Minecraft issue, what I think the issue here is this boat is split between 2 biomes, in Minecraft the shipwrecks use different types of wood depending on which biome it is located in, this is purely for visual effect. As you can see in the screenshots, the spruce and dark oak side is located in a Deep Ocean whereas the other birch side is located in an Ocean There is currently a report open on the MC Jira pertaining to this issue https://bugs.mojang.com/browse/MC-149555?attachmentSortBy=fileName