Minecraft wiki entry for Underwater_home, associated text: An undersea home has certain pros and cons that set it apart from any other sort of base. An underwater home is immune to explosions, most mobs have difficulty attacking it, and it will provide a high level of protection and concealment. Additionally, the base can have access to conduit power. The difficulties with an undersea build in survival mode is that it presents challenges of reduced movement and mining speed, breathing while working, clearing water from the structures, and special measures for entry and exit on deep bases. Also be wary of drowned, as they are fairly common in oceans and sometimes have tridents, which can be very dangerous.