People normally adhere to particular procedures and standards to protect their safety and wellbeing when submerged in water for days at a time. What transpires to humans within a submarine during prolonged underwater operations can be summarized in the following key ways:

Living conditions: Members of the crew are provided with a living environment by submarines. They have dormitories, dining halls, and recreational spaces to help keep morale high. However, due to a lack of room, staff workers frequently have to live in cramped quarters.
Water purification systems and food storage facilities are both included in a submarine’s equipment list. Meals for the team are frequently thoughtfully prepared and packed to offer a healthy diet. Since it is impossible to restock freshwater underwater, freshwater resources can be preserved using recycling and filtration devices.
Work Shifts: Submarine crews normally keep to a rotating watch schedule, with each crew member taking turns working a particular shift. This guarantees that crucial activities like navigation, sonar use, and engine control are continuously monitored and maintained.
Communication: Using antennae and buoys intended for underwater communication, submarines keep in touch with the surface. These systems provide sporadic communication with the outside world, especially for receiving instructions, sending data, and keeping track of the situation.

Long stints underwater can be mentally taxing for the crew because of the seclusion, cramped conditions, and lack of natural light. Psychologists or other support staff are frequently stationed on submarines to address any psychological issues and promote crew morale.
Emergency procedures and strict safety procedures are in place on submarines. To deal with crises like fires, flooding, or equipment breakdowns, crew members receive training. Additionally, life-saving tools like rescue vehicles or escape capsules are carried by submarines.
Repairs and upkeep: To guarantee optimum operation, submarines need routine maintenance. Depending on the nature of the problem, crew members could have to undertake repairs or inspections while submerged.
Overall, a submarine crew’s safety, well-being, and operational capabilities are maintained when they are engaged in prolonged underwater operations. These precautions are in place to guarantee both the crew members’ safety and the mission’s success.