It stops and says why on the action bar rather than dig into water or lava, even water beside or above the next slice, or into chests and other blocks that hold things, spawners, bedrock, obsidian, other mods' blocks, taller sand or gravel, or a drop with no floor. It works only while a player is within 32 blocks and waits while something stands in its way. Pick up what it digs as you follow it: like any dropped items, they vanish after 5 minutes. Breaking it gives back the bore, its torches, and 1 coal for every 4 blocks of fuel left, rounded down. Named coal and torches stay in your hand. Anyone playing in your world can fuel, start or break it.