Certified Flight Registered Nurse (CFRN) Practice Exam

At a depth of 66 feet underwater, a diver is subjected to how many atmospheres of pressure?

1. 1 ATM

2. 2 ATM

3. 3 ATM

4. 4 ATM

The correct answer is: 3 ATM

At a depth of 66 feet underwater, the pressure experienced by a diver is calculated based on the concept that every 33 feet of seawater adds an additional atmosphere of pressure to the surface atmosphere. At sea level, the pressure is already 1 atmosphere (ATM). When a diver goes down to 33 feet, the pressure increases by 1 ATM, making it 2 ATM total (1 ATM for the surface plus 1 ATM for the additional depth). Going down to 66 feet adds another 1 ATM, resulting in a total of 3 ATM. Therefore, at 66 feet underwater, the diver is subjected to 3 atmospheres of pressure: 1 ATM from the surface and 2 ATM from the water above. This understanding of pressure dynamics is crucial not only in diving but also in various fields such as aviation and medicine, where pressure changes can greatly affect physiological responses.