The second mate, or second officer, is the third-highest position on a ship. As a second mate, your job duties include keeping watch, overseeing navigational procedures, preparing voyage plans, and serving as an understudy for the first and second ranking officers on the ship. In general, you need considerable experience working on a ship before being considered for a second mate job, having already honed your skills working through the ranks. You’re in charge of other crew members in your role as the second mate, making leadership skills crucial. You also need to get your second mate license and, depending on the company, additional certifications to prove your qualifications for this career.