Scuba Diving International (SDI) Computer Nitrox Practice Exam

True or False: Dive computers work by monitoring the presence of so-called 'silent bubbles' using ultrasound.

1. True

2. False

3. Somewhat true

4. Not applicable

The correct answer is: False

Dive computers do not use ultrasound or monitor 'silent bubbles' to function. Instead, they are designed to track the diver's depth, time underwater, and nitrogen absorption based on established algorithms, which consider how decompression and saturation work. These algorithms help prevent decompression sickness by calculating no-decompression limits and required safety stops based on the diver's profile. Silent bubbles, often referred to in discussions about decompression sickness, are the nitrogen bubbles that may form in the body tissues if a diver ascends too quickly. However, dive computers do not have the capability to detect these actual bubbles; rather, they operate based on theoretical models and dive profiles to help manage nitrogen loading and ensure safety during and after a dive. This makes the correct response to the statement that dive computers work by monitoring 'silent bubbles' using ultrasound as false.