Skills and Environment Flashcards
(119 cards)
When making a CESA the diver should ____ making an ___ sound
Why
Exhale
Ahhh
Avoid lung over expansion injury
If you tried to forcefully exhale during a CESA this is okay? T/F
False - you want to maintain a constant lung volume, forceful exhalation makes this difficult and it could even trap air in lower portions of the lungs causing an over expansion injury
When making a CESA the diver should do what with his equipment
A) ditch weight belt
B) remove regulator
C) check computer
D) keep all equipment in place
E) maintain regulator in mouth
D E
Otherwise can’t control the swimming ascent
Why bother keeping your regulator in place when ascending during a CESA
Might be able to get a few breaths in as ascend and ambient pressure is reduced
Also if you have an uncontrolled urge to breathe it’s better to do so with regulator in mouth than getting a mouthful of water
Also I’m practice it allows you to breath at any time if needed
Why not ditch your weight belt on ascent in a CESA
Won’t be able to control rate of ascent
During a CESA what should a diver do regarding ascent rate
Maintain normal ascent rate not exceeding 60’/minute
It’s okay to practice buoyant emergency ascents? T/F
False - they can’t be controlled because you removed the weight belt
Weight check at surface how do you do it
Use estimated weight
Breathe from regulator
Empty BCD and hold breath should float at mid eye level and sink when release breath
Then add 5 lbs because if did it with full cylinder the air has weight you need to compensate for
Divers should always wear an amount of weight of 10% of body weight? T/F
False
The only way to know how much weight you need is by trial and error? T/F
True
When conducting a buoyancy check at the surface you should
A) fully inflate your BCD
B) relax holding normal breath in
C) sink slowly when exhale
D) add or subtract until float at eye level
B C D
If when conducting a buoyancy check you need some air in your BCD to float then you need to add/remove weight
What about if you empty your BCD and exhale and still don’t sink
Remove
Need more weight
As you gain more experience you will need less weight because of less displacement from a more relaxed breathing cycle? T/F
True
How much should you add after finishing a buoyancy check to compensate for doing it with a full cylinder?
What is the difference from fresh to salt water
5 lbs
Depends on body weight but about 4-7lbs difference
You should always have your mask on at the surface? T/F
True - helps defogger from washing out, and prevents getting splashed in eyes and can look down to check in buddy
A clenched fist brought to chest is?
Low on air
Signal for:
something wrong
Danger/hazard
Which way
You lead I follow
Boat
How much air do you have
Share air
Out of air
If someone signals out of air you should
Give them your alternate site source
You are out of air and buddy is 20’ away not paying attention, what do you do
Swim to buddy, grab his alternate air source then signal out of air
How do you share air with someone whose alternate air source is their BCD inflator
They need to switch to their BCD inflator and then you use their regulator
What factors determine the type of pattern to be used when conducting an underwater search
Environmental conditions (amount of visibility and if a current is present)
Size of object
When working close to a shoreline what naturally occurring phenomenon can be used as aids to navigation
Sand ripples (generally run parallel to shore)
Changes in water depth
What are means of measuring distance underwater without using a calibrated device:
Which is most accurate
Kick cycles
Arm spans
Arm spans
General distance estimates underwater can be done with
Kick cycles
Timed swims