Sonar uses acoustic waves to detect and locate underwater objects by reflecting sound waves or intercepting sound waves from sources underwater, on the surface, or above water. Whales and dolphins use sonar to communicate. S.C.U.B.A. stands for Self-Contained Underwater Breathing Apparatus and uses a portable supply of compressed gas for breathing while swimming underwater.

1. Exploring the Deep Definitions By: Dylan DuSange & Justin Bebbington

2. SONAR Sonar stands for SO.undNA.vigationR.anging. It is used primarily for the detection and location of underwater objects by reflecting acoustic waves, or by the interception of acoustic waves from underwater, surface, or above-surface acoustic source. Whales and dolphins use sonar to communicate.

3. S.C.U.B.A. S.C.U.B.A. stands for S.elfC.ontainedU.nderwaterB.reathingA.pperatus. the apparatus uses a portable supply of compressed gas (as air) supplied at regulated pressure and used for breathing while swimming underwater.