How many officers would be assigned to a submarine and what were their roles?

There would normally be eight to ten officers on a boat like the Pampanito.

The captain and the executive officer were designated and assigned by the Navy.

1. The captain or commanding officer (CO) was the most senior officer assigned to the boat. He was responsible for the entire ship and all of its actions.
2. The executive officer (XO) was second in line to command. He supported the captain during critical actions. He was usually responsible, subject to the captain’s approval, for personnel assignments and most other administrative matters. He would normally have been qualified for command and able to assume command in case the captain was disabled or died.

Most of the rest of the assignments would change at the discretion of the captain and XO. The most common roles, in general order of seniority, would have been:

1. The operations officer was responsible for navigation and preparing patrol and other operational plans. He may have also managed some of the other officers such as communications and electronics.
2. The engineer was responsible for propulsion, the battery and other mechanical equipment such as pumps and compressors. The engineer was often the battle stations diving officer.
3. The weapons officer was responsible for torpedoes, guns and related equipment.
4. The electronics officer would be responsible for radar, sonar and electronic counter measures (ECM) equipment.
5. The communications officer was responsible for the radio room, keeping the secret library current, drawing communications codes from base, issuing daily crypto codes and destroying them when no longer needed.
6. The supply officer was responsible for ordering needed equipment, supplies and spare parts. He also worked with the lead cook to develop menus and order the needed food.
7. The assistant engineer would support the engineer, usually by being responsible for the non-propulsion equipment such as the pumps and compressors.

These officers, with the likely exception of the CO and XO, would also be standing watches as the officer of the deck (OOD) or diving officer.