These waves break in a stable pattern.

This is a small valve just lower than the mouth that empties the collected water that comes down the tube when one blows it out.

The pressure exerted by the water at equilibrium due to the force of gravity.

This kind of snorkel has the most basic part, the solid tube and the mouthpiece. Sometimes, this can be bent to a specific shape.

An English merchant seaman, developed the first self-contained diving gear that used compressed oxygen and not compressed air.

Holds the mask to the face underwater.

He built the “diving engine,” which was an underwater oak cylinder supplied with compressed air from the surface.

This prevents splashed water and spray from easily entering the tube.

Cushions and protects the nose. Some masks have the purge valve, a little flap valve located at the bottom of nose pocket that helps in removing the water has entered the masks.

This helps prevent the mask from fogging up