Hull maintenance technician (abbreviated as HT) is a United States Navy occupational rating. Hull maintenance technicians plan, supervise, and perform tasks necessary for fabrication, installation and repair of all types of shipboard structures, plumbing, sheet metal fabrication, carpentry and piping systems; organize, supervise, and train personnel in maintenance and hull and mechanical repair; supervise and perform tasks in procurement and issuance of supplies and repair parts; instruct personnel and enforce safety and security precautions; prepare records and reports, and maintain shipboard sewage systems.