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Diving Equipment
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Diving Equipment

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  1. Diving Equipment

  2. Equipment We will cover 3 categories: • basic • essential • useful

  3. Basic equipment • Mask • Snorkel • Fins (& boots)

  4. Masks • Human eyes can’t focus in water • Masks trap a layer of air in front of eyes with a pane of glass

  5. Masks must • form a waterproof seal with the face • have a nose grip to allow equalisation • have tempered glass

  6. Snorkels • Curved rubber tube with mouthpiece • Allow snorkellers to breathe face-down at surface • Some have output valves to expel water

  7. Snorkel valves Without valve With valve

  8. Fins • offer propulsion for minimum effort • allow divers to swim on surface and at depth with speed, endurance and power

  9. Fin types Full-foot Open-heel

  10. Full-foot fins • Fit like a shoe • Worn over bare feet • More common for surface swimming • Warm water only

  11. Open-heel fins • Foot pocket with open heel • Held to foot by springs or straps • Can be worn over boots • More common among divers

  12. Fin straps Plastic buckle Fin springs

  13. Essential equipment • Cylinder • Regulator • Diving suit • Weight system • Buoyancy control device • Depth gauge • Watch

  14. Cylinders

  15. Cylinders • a.k.a. tanks • contain compressed air divers need underwater

  16. Cylinder types • steel or aluminium • 10—15 litre volume • 12 l tanks are most common • Air compressed to 200—300 bar • 2000—4500 litres of air

  17. Regulators

  18. Regulators • Allow us to breathe at appropriate pressure • Pressure reduced in two stages • First stage attached to tank • Second stage attached to mouthpiece • Extra hoses supply air to other equipment • buoyancy control devices, dry suits, etc.

  19. Regulators

  20. Weights

  21. Weights • Humans float in seawater • Especially in diving suits • Weights offset this extra buoyancy • Usually on nylon belt • Other systems: harness, integrated in BCD

  22. Attaching weight belts • Weights should be secure on belt • Belt should be tight around waist

  23. Depth gauges and watches

  24. Depth gauges and watches • Knowing depth and time is essential • Only way to avoid decompression sickness • Gauges and watches must be accurate and reliable • Watches should be rated to 100 m • Most divers use dive computers

  25. Diving suits

  26. Diving suits • Irish seawater surface temperature range: 7°—15°C • Hypothermia is a risk • Protective thermal clothing is necessary

  27. Suit types Semi-dry suits Drysuits

  28. Wet suits • Two-piece suits • long johns • jacket with hood • Neoprene body: 3—8 mm • Neoprene wrists and seals

  29. Wet suits • Provide insulation through suit material • Trap a layer of water against skin, which is warmed by body

  30. Neoprene Foam rubber Nylon lining

  31. Neoprene • Foam rubber core • Bubbles are kept separate to avoid absorption • Fabric outer layer for strength and durability • Excellent thermal protection

  32. Dry suits • one-piece suits with single zip opening • Boots attached • Hoods are usually separate • water-tight neck and wrist seals • Latex or neoprene

  33. Dry suits • Insulate through material and/or undersuits • trap a layer of air between diver and water • Air added/removed through valves

  34. Neoprene dry suits • neoprene: 4—9 mm • provide built-in insulation • are cheap(er) to maintain

  35. Membrane suits • Thin material • no thermal protection • usually non-stretch • Require insulating undersuits

  36. Dry suit seals Neoprene seals • Long-lasting • Non-allergenic • Form a less effective seal than latex Latex seals • Need replacing every 1–2 years • More flexible • Form a tighter seal

  37. Dry suit zips Rear-entry Front-entry

  38. Buoyancy control devices

  39. Buoyancy control devices a.k.a. BCDs provide • face-up flotation at surface • buoyancy control at depth

  40. Buoyancy control at depth • Underlying theory in Buoyancy lecture • At depth: air is added to BCD • On ascent: air is removed

  41. BCD design • Inflatable internal bladder • direct-feed hose from regulator • Inflation mouthpiece • Inflate/deflate valves • Overpressure valves

  42. BCD use • Surface life jacket • Buoyancy adjustment • Alternate air supply

  43. BCD use Surface life jacket • Allows you to rest at surface • Protects incapacitated divers • Helps when waiting for the boat

  44. BCD use Buoyancy adjustment • Pressure compresses diving suits at depth • Adding air to BCD compensates for this... • ...but needs to be removed on ascent

  45. BCD use Alternate air supply • Most BCDs allow you to breathe through the inflation mouthpiece • This is emergency-only and requires training and practice

  46. BCD precautions • Avoid uncontrolled ascents • vent air gently and gradually on ascent • Don’t use as a lifting device • Dump air during ascent • not before

  47. Useful equipment • Knife • Torch • Dive computer • Safety marker • Kit bag

  48. Knives • Useful for cutting out from entanglements • Must be secured • locking sheath or lanyard • Line/net cutters are also useful

  49. Torches Useful for • Adding light • Returning colour • Night diving

  50. Dive computers • Comparatively recent development • Constantly recalculate depth and time • Help to avoid decompression sickness