1. Diving Equipment

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

3. Basic equipment Mask Snorkel Fins (& boots)

4. Masks Human eyes cant 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 valveWith 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-footOpen-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 buckleFin springs

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

14. Cylinders

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

16. Cylinder types steel or aluminium 1015 litre volume – 12 l tanks are most common Air compressed to 200300 bar – 20004500 litres of air

17. Regulators

18. 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. 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. 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. Irish seawater surface temperature range: 7°15°C Hypothermia is a risk Protective thermal clothing is necessary

27. Suit types Semi-dry suitsDrysuits

28. Wet suits Two-piece suits – long johns – jacket with hood Neoprene body: 38 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: 49 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-entryFront-entry

38. Buoyancy control devices

39. 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 Dont 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

51. Safety markers Allow coxswains to track you Keep other boats away Reduce waiting time for boat pick-up

52. Kit bags Keep your kit ship-shape on board Can be mesh or waterproof

53. Care and maintenance General care and maintenance Equipment-specific care and maintenance

54. General care and maintenance Wash everything in fresh water after diving Dry in the shade – rubber degrades in sunlight – cylinder pressure increases in sunlight

55. Maintaining diving suits Wash in fresh water after dive Dry in the shade Wash zips (and lubricate dry suit zips) Store on hanger away from sunlight

56. Maintaining BCDs Visually inspect for damage Test direct-feed and mouthpiece Check overpressure valves Check mouthpiece dump valve Check it fits comfortably Periodically sterilise internal bladder

57. Questions

58. 1. The snorkel is designed to (b) permit breathing on surface The snorkel is used for breathing in a face-down position, on surface

59. Questions 2. Seeing through a mask is achieved by (a) placing a layer of air between eyes and water Our eyes see clearly in an air medium. Water must be kept out by the mask.

60. Questions 3. The mask should cover your nose to allow pressure equalisation

61. Questions 4. Basic equipment consists of (c) Mask / snorkel / fins

62. Questions 5. Which of the following items of equipment are essential? (a) & (c)

63. Questions 6. Wet suits are worn in cold water to keep a diver (c) They keep the diver warm by acting as insulation and by reducing the flow of cold water around the body

64. Questions 7. Wet suits are made of (b) Foam neoprene Foam neoprene: a rubber filled with neoprene gas bubbles which insulates the body from cold and is resistant to corrosion from oil, salt, and sun

65. Questions 8. Wet suits should be (c) Close fitting Close-fitting suits will slow down the flow of cold water thus keeping the diver warm and minimising heat loss

66. Questions 9. Dry suits will (b) keep you warmer than a wetsuit Generally, the dry suit will be warmer than the wetsuit because of the insulation worn next to the skin (provided that it does not leak).

67. Questions 10. Semi-dry suits have seals to keep (b) water in the suit Semi-dry suits have seals to retain water warmed by body heat.

68. Questions 11. A buoyancy device is (b) essential A buoyancy device is essential to divers and should be worn travelling to and from the dive site, as well as during the dive.

69. Questions 12. The buoyancy control device is designed (c) to maintain a face-up position on surface A properly-designed buoyancy device will provide a face- up position on surface, which may be required if a diver is tired or has had an accident.

70. Questions 13. The buoyancy device inner bladder should be sterilised regularly to (a) preserve internal hygiene Inside the buoyancy is warm and damp: an ideal breeding ground for germs.

71. Questions 14. The buoyancy device should be washed (b) immediately after use Wash often in fresh water: warm water if possible. This will prevent soft corrosion from the sea and chlorine corrosion from swimming pools.