Chapter 3 - Safe Diving And Diver Rescue

Question 1

What must be considered when dive planning?

Answer 1

Dive objective 
Work to be done
Permission required from authorities? 
Weather conditions 
Tools required
Competent for task
Has the project plan been followed

Question 2

What are the preparations for the diver?

Answer 2

Listen to the dive brief
Understand all aspects of the work
Be honest if you have never used the tools before
Check equipment
Ensure items aren’t defective
Conduct a buoyancy check with new equipment

Question 3

How do you get the correct buoyancy?

Answer 3

Weight for neutral buoyancy at the start of the dive and then add 2-4kg to compensate for the weight of the air used in the dive

Question 4

How should you enter the water?

Answer 4

Enter using the method dictated by the supervisor, swim to the shot line and exchange the ok signals

Question 5

How should you descend?

Answer 5

Use the shot and use your bcd to control the rate. Check Depth and stay within the limits

Question 6

What will you do whilst under the water?

Answer 6

Move to the worksite
Maintain visual contact
Monitor each other checking air, time and depth

Question 7

When should you begin the ascent?

Answer 7

When the task is complete
The allocated bottom time has been reached
The air pressure in the main cylinder drops to the minimum required to make a safe ascent.

Question 8

What do you do during the ascent?

Answer 8

Face each other and stay level
Vent air from the drysuit
Control the smb line - don’t let it become slack
Complete stops 
Surface directly beneath the smb

Question 9

What are the standard safety stops of Plymouth university?

Answer 9

1 minute - 3/6 m with max depth of 19m

3 minutes - 3/6m with depths over 19.1m

Question 10

What should you do at the surface?

Answer 10

Check for danger
Achieve positive buoyancy
Check each other
Signal OK
Watch the dive boat during approach
Exit the water using method stated in the brief
Report dive details to the supervisor 
Strip, clean and stow equipment 
Help on deck
Listen and take part on debrief

Question 11

How do you avoid accidents?

Answer 11

Dive defensively - keep within the no stop section of the tables 
Maintain equipment
The 6ps
Practise skills regularly
Maintain personal fitness levels

Question 12

What are the 6ps?

Answer 12

Prior planning and preparation prevents poor performance

Question 13

What are the common causes of accidents?

Answer 13

Running out of air
Diver separation
Separation of divers from surface cover boat
Diving beyond limits

Question 14

What are the reasons for aborting a dive?

Answer 14

Visibility deteriorates 
Conditions deteriorate
Equipment failure
Medical problems
Diver separation
Diver is unable to handle the conditions safely
Gas levels dictate
Max depth is exceeded

Question 15

What should you do if separated underwater?

Answer 15

Stop where you are
Look 360°
If you can see your team/buddy rejoin them
If you can’t see them, safely return to the surface
Don’t look underwater or descend again once reaching the surface

Question 16

What should you do if separated from the dive boat?

Answer 16

Achieve positive buoyancy
Stay breathing from the dive cylinder as long as possible
Remain vigilant
Use whistles, flares or strobes etc

Question 17

What should you do if you run out of air?

Answer 17

All working divers carry a bailout so when you run out of air you can switch to it and make a controlled ascent. If that fails use your partners bailout

Question 18

What should you do if there is a problem with the main cylinder and it’s regulator.

Answer 18

Swap to the bailout and try to fix the situation

Question 19

How would you fix a free flow?

Answer 19

Turn of the main cylinder
Allow short time for the valve to thaw
Reopen cylinder and check for continued free flow
If stopped check gauges and continue dive if safe.
If not make a controlled ascent with the bailout

Question 20

What else could you use to control out of air situations?

Answer 20

Alternative air sources
H valves
Twin sets
Combined breathing regulator

Question 21

What should be the qualities of the alternate air source?

Answer 21

Easy to identify
Conspicuous
Accessible

Question 22

What is the routine for shared air?

Answer 22

Give out of air signal and use the donors alternate source
Positive grip established and then a controlled ascent
Establish positive buoyancy and signal the boat
If both divers are okay just give the OK signal

Question 23

What is the last resort?

Answer 23

Diver signals out of air
Donor offers prime demand keeping hold of it and a two breath rhythm is established
Hold onto each other and make the ascent

Question 24

What are the two methods to use of there are no other air sources?

Answer 24

The free ascent - swim steadily to the surface exhaling continuously

The buoyant ascent - dump weight belt or inflate BCD with the emergency cylinder if available. Flare body to reduce ascent rate. Look up and exhale forcibly

If either of these methods are used give the distress signal

Question 25

What is a standby diver?

Answer 25

Someone there to help control the situation. May either be in the water or on deck

Question 26

What should the standby diver do when called into the water?

Answer 26

Swim to the divers lifeline
Hold the lifeline and follow it to the diver - not pulling on it
Free any tangles in the lifeline if they are minor
When the diver is found tug the lifeline 5 times
Hold the victims head at a natural angle and pull the lifeline 5 more times to signal hoist the diver

Question 27

How should they go about in hoisting the victim?

Answer 27

At a steady rate
The standby should control the venting of air from the drysuit and BCD
Immediately dump the victims weightbelt at the surface

Question 28

How do you manage the diver and their equipment at the surface (standby?)

Answer 28

Ditch weight belt - buoyant
Start removing equipment
Move the scuba unit aside and push the victims legs down with them facing the pontoon
Pass the scuba unit up

Question 29

What does the standby diver do if the diver is fine?

Answer 29

On the diver
One pull - attention
One pull - all is well

On themselves
One pull - attention
Four pulls - permission to come to the surface