Larry Wedgewood Scuba Diving Instruction

The Effects of Decreasing Pressure on Body Air Spaces

Lesson 9

Snorkles

Course Complete

Watch the video above and then answer the quiz questions below

Although scuba equipment supplies air, snorkels are standard equipment for scuba diving for several reasons. At the surface, a snorkel saves your air supply while your face is in the water and makes it easier to breathe when there’s chop or splashing waves that could get into your mouth. It also allows you to save air when you look underwater (to adjust your gear or see what’s below) or swim with your face in the water (much less tiring than repeatedly lifting your head to breathe). A snorkel is even more important for these purposes if you come up with little air remaining and have a moderately long swim to the boat or shore, or have to wait in the water while other divers exit.

Quick Quiz

Open Water Course Lesson quiz

1. The most important rule in scuba diving is to

check your air supply every five minutes.

breathe continuously and never hold your breath.

always dive with a buddy.

2. Failure to follow the most important rule in scuba diving can cause severe lung over-expansion injuries, which can result in paralysis or death.

True

False

3. During ascent I feel discomfort in my ears. I should

continue my ascent at a slightly faster rate.

stop, descend slightly and allow trapped air to work its way out.

use a decongestant before my next dive.

equalize by blowing gently against blocked nostrils.

Module One

Water Pressure and Air Volume Effects

The Effects of Increasing Pressure on Body Air Spaces Topic 2 of 6

The Effects of Decreasing Pressure on Body Air Spaces Topic 3 of 6

Breathing Underwater

Buoyancy and Controlling Buoyancy Topic 5 of 6

The Buddy System

Choosing and Caring for Scuba Equipment

Dive Masks

Snorkles

Fins

Scuba Kit

BCD (Buoyancy Control Device)

Regulators

Scuba Cylinders

Weight Systems

How to Defog Your Mask

Setting Up Your Scuba Kit

Inflating and Deflating Your BCD

Gearing Up With Your Buddy(ies)

Breathing Underwater

Hand Signals

Regulator Clearing

Regulator Recovery

Clearing Water Out of Your Mask

Managing Your Air Supply

Descending and Equalizing

Swimming Underwater

Alternate Air Source (AAS) User

Ascents and Returning to the Surface

Emergency Weight Drop

BCD Oral Inflation at the Surface

Exiting the Water

After the Dive

Knowledge Review One

Module One Quiz

Course Complete