I built an ark (ship) but not in the water but on a straight meadow. But I would like to build other things there but I would have to destroy the ark. Is there a mod with which you can move objects in Minecraft? I would then simply place the ship in the water.
Look for the mod / plugin WorldEdit. That should be able to edit your Minecraft worlds, but be careful, it could also crash your Minecraft.
You can use the Command Block to copy the area where the ark is located to another location. Disadvantage: you can only put it on the same world with it
