530 likes | 691 Views
NOAA Standard Drysuit Diving Outfit. Presented by the NOAA Diving Center Seattle, Washington. Global View. Introduction NOAA Standard Drysuit Diving Outfit Components Diving procedures Safety precautions Key Points Self test. Introduction.
E N D
NOAA Standard Drysuit Diving Outfit Presented by the NOAA Diving Center Seattle, Washington
Global View • Introduction • NOAA Standard Drysuit Diving Outfit • Components • Diving procedures • Safety precautions • Key Points • Self test
Introduction • The NOAA standard drysuit diving outfit consists of the following primary components: • Drysuit • Buoyancy compensator device (BCD) • Diving Unlimited International Weight and Trim System (DWTS) • Scuba cylinder • Primary and secondary regulators/gauge console • This presentation is intended for those NOAA divers that have not received training in the use of drysuits with BCDs.
NOAA Standard Drysuit Outfit Mask & Snorkel BCD inflator under velcro Primary regulator Shadow regulator Suit fill whip under right arm Exhaust valve Whistle BCD DWTS – right hand release Console runs under left arm Fins Knife Ankle weights
DUI Weight & Trim System • The DUI Weight & Trim System (DWTS) yellow weight ditch handles should be easily accessible • Place heaviest weights in front pouches • Distribute weights evenly on both sides
Back view DWTS Positioning • The ‘X’ in back harness webbing should be positioned between shoulder blades • Weight pouches should be positioned below hips • DWTS is worn under BCD
Outfit Assembly-1 • The BCD is worn in the standard configuration • The drysuit power inflator hose is connected to the LP port of first stage regulator and runs under right shoulder
The drysuit inflator valve is rotated towards diver’s right side The BCD inflator hose and Shadow run over left shoulder and are secured with the Velcro strap Outfit Assembly-2
Ensure that the BCD chest strap (if used) does not obstruct the drysuit inflator valve Ensure that the DWTS release handles are easily accessible Pressure gauge console hose runs under left shoulder Ensure the drysuit exhaust valve is unobstructed Outfit Assembly-3
Weighting-1 • Initial adjustments: • Adjust weight to achieve neutral buoyancy at the surface with the drysuit and BCD vented completely • Add five pounds to compensate for air breathed from cylinder during dive • Distribute weight to achieve horizontal trim (test at depth) • Ankle weights are mandatory
Weighting-2 • Final adjustments: • Hover (no swimming) at 15 fsw with 500 psi in tank • Adjust weighting and retest weight distribution
Buoyancy Control • The adjustable volume of air inside the drysuit is used to control the diver’s buoyancy underwater. This allows for the diver to only have to vent one source of air in an emergency uncontrolled ascent to the surface. • The BCD is used for surface floatation only, unless the drysuit becomes flooded underwater, then the BCD is used for buoyancy control.
DWTS Ditching • To ditch the weights, grab a ‘yellow’ handle and pull forcefully away from your body • Hold weight pouches away from all other equipment and release • The DWTS is designed to allow the ditching of ½ the weight independently
DWTS Re-weaving • At the completion of re-weaving the DWTS, ensure the free-end of the ‘yellow’ cord is tucked away. • Do not tie free ends together. • Periodically check pouches for proper assembly as cords will loosen with time.
Descending-1 • Use the drysuit exhaust valve to manually vent air from the suit to allow descent • Kelp dive preferred over pike dive (air into feet) • Snort air into mask & under hood during descent to prevent external ear squeeze
Descending-2 • Add just enough air to the suit to control buoyancy and to reduce the effect of suit squeeze • Should the drysuit inflation valve stick in the open position, immediately disconnect the inflation hose and abort the dive
Ascending • Begin kicking to the surface • Adjust dry suit exhaust valve to release excess air and position valve at highest point • Add air in short bursts (about 2 seconds), wait for effect • Monitor ascent rate (30 fpm) and be ready to manually exhaust excess air from the suit • Once at the surface inflate BCD for surface floatation
Emergency Venting • If rapidly expanding air inside the drysuit cannot be vented via the auto/manual suit exhaust valve, emergency venting procedures must be initiated immediately using either, or both of the following techniques: • Breaking the neck seal • Breaking the wrist seal
Managing Excess Buoyancy-1 • Problem: Out-of-control ascent due to loss of weight belt, stuck inflator valve, or over-filling suit • Recommended corrective actions: • Try to grab hold of a stationary object (e.g., bottom, downline, piling, etc.) to buy time to take corrective action • Manually vent suit • Perform an emergency “rollout” procedure • Flare-out, spread eagle to increase drag • Because of the potential for lung barotrauma, the diver should exhale during ascent
Forward roll Head down Strong kick down & around into a head up Left arm up and bent Flared position Exhale Backward roll Back arched Strong kick to head up Left arm up and bent Flared position Exhale Managing Excess Buoyancy-2
Managing Loss of Buoyancy • Problem: Loss of positive buoyancy due to inability to inflate suit or flooding of suit. • Recommended corrective actions: • Use BCD to assist in swimming to surface • If BCD unavailable, even a flooded suit can be swum to the surface • Surface at normal rate and exit water (which may be difficult and may require removing or cutting and drain the suit) • Consider dropping half or all weights • Check and continue to monitor for hypothermia
Drysuit Use a buoyancy compensation device for surface flotation and emergency back up Know your equipment and emergency procedures Practice your drysuit diving skills under controlled conditions until they become second nature Ensure your dive partner is familiar with your drysuit system Use the correct amount of insulation for the water temperature and exercise rate while diving Safety Precautions-1
Drysuit Con’t. Proper weighting should allow you to make a safety stop at fifteen feet upon completion of your dive with a cylinder containing 500 psi (34 Bar) of air Check your valves, zipper and seals before each dive Perform routine preventive maintenance on drysuit and valves regularly If additional servicing is needed have it performed by a qualified repair technician only Safety Precautions-2
DUI Weight & Trim System Always check to ensure that all of the weight pockets are securely closed before donning the DWTS Use right hand to release weights on right side and left hand for left side weights Do not dive with the DWTS system unless you are able to operate the release cords properly Do not thread the waist belt through the DWTS weight release handles Do not use the DWTS unless you have practiced and mastered the weight ditching procedure Safety Precautions-3
DUI Weight & Trim System Con’t. Overfilling the weight pouches prevents the flaps from fully engaging the pile on the pockets and the weights will not be held securely in the pouches Always ensure there is sufficient positive buoyancy in drysuit before removing BCD while wearing the DWTS Safety Precautions-4
Buoyancy Compensator Device In an emergency do not depend solely upon a BCD to lift you to the surface, be prepared to swim and even drop some or all your weights if necessary Be prepared to use the oral inflation function of the power inflator to add air to the BCD in the event the power inflator mechanism fails Never use your BCD (or drysuit) to lift heavy objects (>10lbs) underwater Do not attempt to breathe the air in the BCD due to potential contamination Safety Precautions-5
Buoyancy Compensator Device Con’t. Never be weighted so heavily with your diving system that you cannot establish immediate positive buoyancy at the surface by ditching your weights Before each use, be sure to soak the cylinder bands in water before attaching the BCD to the cylinder Ensure that the BCD does not interfere with operation of the drysuit inflator valve or exhaust valve, or the weight pouch release handle of the DWTS Safety Precautions-6
Key Points • The primary components of the NOAA standard drysuit diving outfit include: suit, DUI weight and trim system, BCD, scuba cylinder, and primary & secondary regulators with gauge console • The use of the above outfit requires special training • The drysuit is used for underwater buoyancy control; whereas, the BCD is used for surface floatation • Adjust weight to achieve neutral buoyancy at the surface with the drysuit & BCD vented completely • Be prepared to manage suit control problems – uncontrolled blow-ups are the most dangerous emergency situation that can occur and must be prevented
NOAA Standard Drysuit Outfit • QUESTION #1: A diver should adjust weight to achieve ______ buoyancy at the surface with the drysuit and BCD vented completely. • Positive • Neutral • Negative • B or D, but not A • ANSWER: B. Neutral
NOAA Standard Drysuit Outfit • QUESTION #2: True or False: The heaviest weights should be placed in the rear pouches of the DUI W&TS. • True • False • ANSWER: B. False
NOAA Standard Drysuit Outfit • QUESTION #3: When worn correctly, the weight pouches of the DUI W&TS should be positioned: • Above the diver’s hips • At the diver’s hip • Below the diver’s hips • Lower in the front than in the rear • ANSWER: C. Below the diver’s hips
NOAA Standard Drysuit Outfit • QUESTION #4: True or False: The DUI W&TS is designed to allow the ditching of weights from either side independent of the other side. • True • False • ANSWER: A. True
NOAA Standard Drysuit Outfit • QUESTION #5: True or False: When properly configured, the drysuit inflator hose is routed under the diver’s left arm. • True • False • ANSWER: B. False. It runs under the diver’s right arm
NOAA Standard Drysuit Outfit • QUESTION #6: True or False: In normal operations, underwater buoyancy is controlled using the BCD; whereas surface flotation is controlled by the drysuit. • True • False • ANSWER: B. False
NOAA Standard Drysuit Outfit • QUESTION #7: The maximum amount of air that should be maintained in a dry suit at depth is the minimum amount necessary to: • Prevent suit squeeze • Maintain required buoyancy • Offset loss of buoyancy from items collected underwater • Both A and B, but not C • ANSWER: D. Both A and B, but not C
NOAA Standard Drysuit Outfit • QUESTION #8: True or False: The preferred surface dive to use with a dry suit is the pike dive. • True • False • ANSWER: B. False. The kelp dive is preferred
NOAA Standard Drysuit Outfit • QUESTION #9: Arrange the following in order of priority. If diving in a dry suit and you feel yourself floating upward feet first, you should: • Flare out to slow the rate of ascent • Try to grab hold of something • Invert yourself and vent the suit by pulling on a seal • Invert yourself and vent the suit by using the exhaust valve • ANSWER: B, D, C, A
NOAA Standard Drysuit Outfit • QUESTION #10: The amount of weight required for a specific drysuit ________. • Is directly related to the type of undergarment worn • Is not related to the type of undergarment worn • Is inversely related to the type of undergarment worn • Is the same for a ¼” wetsuit in saltwater • ANSWER: A. Is directly related to the type of undergarment worn
NOAA Standard Drysuit Outfit • QUESTION #11: The most dangerous emergency situation that can occur with dry suit diving is: • A flooded suit • An uncontrolled ascent • A stuck inflator valve • A leaking exhaust valve • ANSWER: B. An uncontrolled ascent
NOAA Standard Drysuit Outfit • QUESTION #12: True or False: The use of either a BCD or DUI W&TS with a drysuit is optional? • True • False • ANSWER: B. False. They are both required