Chapter 3 - Safe Diving And Diver Rescue Flashcards
What must be considered when dive planning?
Dive objective Work to be done Permission required from authorities? Weather conditions Tools required Competent for task Has the project plan been followed
What are the preparations for the diver?
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
How do you get the correct buoyancy?
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
How should you enter the water?
Enter using the method dictated by the supervisor, swim to the shot line and exchange the ok signals
How should you descend?
Use the shot and use your bcd to control the rate. Check Depth and stay within the limits
What will you do whilst under the water?
Move to the worksite
Maintain visual contact
Monitor each other checking air, time and depth
When should you begin the ascent?
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.
What do you do during the ascent?
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
What are the standard safety stops of Plymouth university?
1 minute - 3/6 m with max depth of 19m
3 minutes - 3/6m with depths over 19.1m
What should you do at the surface?
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
How do you avoid accidents?
Dive defensively - keep within the no stop section of the tables Maintain equipment The 6ps Practise skills regularly Maintain personal fitness levels
What are the 6ps?
Prior planning and preparation prevents poor performance
What are the common causes of accidents?
Running out of air
Diver separation
Separation of divers from surface cover boat
Diving beyond limits
What are the reasons for aborting a dive?
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
What should you do if separated underwater?
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
What should you do if separated from the dive boat?
Achieve positive buoyancy
Stay breathing from the dive cylinder as long as possible
Remain vigilant
Use whistles, flares or strobes etc
What should you do if you run out of air?
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
What should you do if there is a problem with the main cylinder and it’s regulator.
Swap to the bailout and try to fix the situation
How would you fix a free flow?
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
What else could you use to control out of air situations?
Alternative air sources
H valves
Twin sets
Combined breathing regulator
What should be the qualities of the alternate air source?
Easy to identify
Conspicuous
Accessible
What is the routine for shared air?
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
What is the last resort?
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
What are the two methods to use of there are no other air sources?
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
What is a standby diver?
Someone there to help control the situation. May either be in the water or on deck
What should the standby diver do when called into the water?
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
How should they go about in hoisting the victim?
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
How do you manage the diver and their equipment at the surface (standby?)
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
What does the standby diver do if the diver is fine?
On the diver
One pull - attention
One pull - all is well
On themselves
One pull - attention
Four pulls - permission to come to the surface
