Revision and assessment
0 of 3 hands-on
01 Introduction
This lesson brings the course together. Use the tables and cards to check your memory, try the review questions, and then take the final exam when you feel ready.
Objectives
- Recall the main points about each part of a scuba kit
- Apply what you know to short equipment scenarios
- Prepare for the final exam
02 Watch
The whole kit
4 min · Video in production
- 1
A diver assembling a kit step by step, with each item labelled as it is fitted.
- 2
A pre-dive check: gas on, breathe, inflate, check weights and signal devices.
- 3
A diver rinsing, drying and storing the kit after the dive.
- 4
A preview of the final exam format and pass mark.
03 Learn
The course at a glance
| Topic | Key idea | Habit |
|---|---|---|
| The system | Six jobs: gas, buoyancy, vision, movement, warmth and information | Choose, fit and check kit as a system |
| Cylinders and valves | Steel or aluminium. Volume times pressure gives gas. Check test date. Yoke or DIN | Never force a connection. Secure cylinders |
| Regulators | First stage lowers cylinder pressure, and the second stage delivers gas at ambient pressure | Breathe from it before every dive. Keep it clean and serviced |
| BCDs | A bladder that changes buoyancy. Know the inflator, dump valves and weight release | Check it before each dive |
| Mask, snorkel and fins | A mask needs an air space. Fit matters | Test fit without the strap. Carry a spare strap |
| Exposure protection | Water takes heat about 25 times faster than air | Dress for the water, and end the dive if you shiver |
| Weighting | Weight cancels buoyancy. Salt, suit and cylinder change how much | Do a weight check, and be able to release it |
| Gauges and computers | Gauge shows gas. Computers use average models | Stay well within limits and use your own computer |
| Accessories | Markers, whistles, cutting tools and lights | Clip them securely and learn to use them |
| Transport and storage | Heat raises pressure and damages kit | Secure cylinders and store kit cool and dry |
| Cleaning and care | Salt corrodes | Rinse, dry, service and record |
A pre-dive check in order
- 1.Check that the cylinder is in test, secure on the BCD and has the right valve.
- 2.Connect the regulator, open the valve fully and check the gauge.
- 3.Breathe from the primary and the alternate, and check for leaks.
- 4.Check the BCD inflates, holds gas and deflates, and that the weight release works.
- 5.Check mask, fins, computer, signalling devices and any other accessories.
- 6.Check with your buddy, and confirm your plan.
Quick numbers
- A 12 litre cylinder at 200 bar holds about 2,400 litres of gas at surface pressure.
- Air weighs about 1.2 grams per litre.
- Water removes heat about 25 times faster than air.
- Salt water is about 2.5% denser than fresh water.
- A mask magnifies by about a third.
- Gas pressure rises about 10% for a 30 degree Celsius rise in temperature, as in a hot car.
Take a guess first
A cylinder holds 15 litres and is filled to 200 bar. About how many litres of gas, at surface pressure, does it hold?
04 Explore
Try it yourself
Test yourself: flip each card to check the answer.
Flip each card to check your answer.
Tap a card to flip it.
05 Apply
Scenario
You are preparing for a boat dive. You notice that your regulator's second stage has a cracked mouthpiece, your BCD is slightly stiff in one dump valve and your weight release is partly hidden under a strap.
What is the right course of action?
06 Check
07 Summary
Key points
- A scuba kit does six jobs, and each piece must be chosen, fitted and checked.
- Know cylinders, regulators, BCDs, weights, instruments and accessories, and how to check them before every dive.
- Protect equipment from heat, salt and knocks, rinse it, dry it and have it serviced.
- When you are ready, take the final exam.
Before you apply this in the water
- Have I been trained by a qualified instructor for this?
- Am I medically fit to dive?
- Do I have a buddy and a plan?
- Am I diving within my training and limits?
Answer every question in the Check section to mark this lesson complete.