With the release of 1.13 water mechanics were changed very drastically and they really fuck up a lot of things. In 1.8 (1.9?) TNT now flows in water and sand stacking was kinda fucked so cannons are very inconsistent and a lot of the bigger ones (reference a leinadarcher cannon or left shooter) really can't be built on 1.12. On 1.13 slabs can now be watered, with *half-slab* like water inside of the half-slab block. This completely fucks over raiding and with items floating in water now this makes water systems for automatic farms kind of wonky. Please do not update to 1.13.