Act as the Captain's second in command.
What does a First Mate do?
The First Mate is the second in command of a large yacht or fishing vessel. While the First Mate almost always works under the command of the Captain, if an emergency arises and the Captain is unavailable, the First Mate leaps into the void and provides leadership and instructions.
As the First Mate, you’re responsible for making sure the exterior of the ship is clean and without damage of any sort. Each day, you perform a thorough inspection of the ship and write down any problems you find. You show the list to the Captain, and direct other crewmembers to fix those problems, pronto. You also supervise the loading and unloading of cargo, making sure the ship isn’t damaged and the items are put away properly.
You put together a list of duties for the crew, and make sure people report to their positions on time and perform their tasks well. If someone cannot work due to illness, you step in and take over. You know how to do nearly every job on the ship.
If a fire breaks out, the ship runs aground, or some other accident occurs, you take over control of the ship until the Captain arrives. You direct the crew to deal with the emergency, and radio for assistance if needed. You keep your voice low while doing this rather than shrieking in the higher registers.
You spend much of your day on the bridge of the ship, assisting with navigation and performing any other task the Captain asks of you. You may also perform formal watches, where you make sure the ship is navigating through the course without heading toward danger.