My present job is, I teach operations and maintenance on the navigation command and control system located on the mine warfare ships. The operators actually use the system.
Maintenance is for upkeep and when it breaks, somebody has to fix it.
It's the eyes and ears of the ship. When you're navigating a mine field, you don't want to run into any mines, and you want to be able to process the contacts. The SYQ-13 is the system that allows the mine warfare ships that are hunting the mines to go into the mine field and locate the mines. You'd want to locate the mines before you go into an area that is suspected to have mines laid.