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255 Scuba Diving Questions with Answers
Greg - 8/07/2013 1:49 PM
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Category: Educational
Comments: 4
The following list of Scuba Diving Questions/Terms and Answers has not been completely reviewed. I found it online and figured it could help divers refresh their knowledge or prepare for an exam.

More Scuba Diving Quizzes can be found on DiveBuddy here:


1. Conditions that affect you when diving.

2. What is a thermocline?

3. Waves create surge which you avoid by _____.

4. Long shore currents tend to _____.

5. You can recognize a rip current by _____.

6. If caught in a rip you should _____.

7. An up-welling tends to cause _____ dive conditions.

8. Tides effect dive conditions by _____.

9. Generally the best tidal level for diving is _____.

10. 4 Steps to assist another diver

11. Panicking at surface of water

12. With an unresponsive diver, what is the primary concern?

13. If a diver loses consciousness or becomes unresponsive, what do you do?

14. If a diver shows symptoms of lung over expansion, what do you do?

15. When you make changes to your buoyancy, at what speed should you make changes, and why?

16. What do panicked divers typically do?

17. If you have a problem at the surface, you should..

18. What is the head?

19. What is the bow?

20. What should you do if you find poor conditions at your dive site?

21. What are two types of interactions that you can have with aquatic life?

22. Nearly all injuries from aquatic life result from _____.

23. What do you do if you see an aggressive animal underwater?

24. Why should you follow fish and game laws?

25. To avoid injuring aquatic animals, you should

26. How do you avoid bottom contact?

27. What are the 6 general types of bottom compositions?

28. What causes currents?

29. If there is a current, you should begin your dive _____.

30. What is underwater visibility?

31. What are the three factors that affect underwater visibility?

32. What three things can restricted visibility cause?

33. When you are diving in clear water, you should use a _____ or _____ when ascending and descending.

34. As you descend the water temperature gets _____.

35. If you know there’s a thermocline, in dive planning you should_____.

36. neutrally buoyant

37. positively buoyant

38. negatively buoyant

39. Objects are more likely to float in _____ water.

40. Salt water is _____ dense than fresh water.

41. What is the most important rule in SCUBA diving?

42. What could happen if you hold your breath when SCUBA diving?

43. Why is buoyancy control at the surface and under water important?

44. What two items control a diver’s buoyancy?

45. How does lung volume affect buoyancy?

46. What are your body’s natural air spaces?

47. What are two artificial air spaces?

48. Why do you usually only feel changing pressure in your body’s air spaces?

49. Why are pressure changes while ascending or descending underwater much more substantial than pressure changes when ascending or descending the same distance in air?

50. What is the relationship between increasing and decreasing depth and water pressure?

51. What is the relationship between air volume and density?

52. How can you equalize the air space in your mask?

53. What is equalization?

54. What is the pain you will feel if you don’t equalize called?

55. How can you equalize?

56. What do you do if you cannot equalize?

57. What do you do if you feel a squeeze while you are descending?

58. What are three reasons we use the buddy system?

59. Underwater, what do objects look like?

60. Why does it get darker as you go deeper?

61. When you are underwater, sounds:

62. Water absorbs heat about _____ times faster than air.

63. What should you do if you are shivering continuously?

64. What is hypothermia?

65. What is the best way to move underwater?

66. For maximum efficiency, underwater, how should you breathe?

67. What is airway control?

68. What are the two types of weight systems?

69. What is the most important feature of a weight system?

70. What happens if you are properly weighted?

71. What is an alternate air source?

72. Why does the alternate air source need to be clearly marked?

73. What are dive knives supposed to be used as?

74. What are dive knives NOT supposed to be used as?

75. absolute pressure

76. actual bottom time

77. ambient pressure

78. Archimedes principle

79. arterial gas embolism

80. barotrauma

81. bends

82. bezel

83. blowout plug

84. Bourdon tube

85. Boyle’s law

86. burst disk

87. capillary gauge

88. cavern

89. caves

90. C-card

91. ceiling

92. ciguatera

93. closed-circuit

94. compartments

95. compass course

96. compass heading

97. console

98. contingency plans

99. controlling compartment

100. Dalton’s law

101. decompression illness

102. decompression stops

103. defogging

104. DIN valve

105. dive profiles

106. diver’s push ups

107. down-welling

108. drift

109. eardrum

110. ebb

111. eddies

112. embolism

113. emergency decompression

114. equalization

115. eustachian tube

116. Farmer Johns

117. fetch

118. fetch length

119. flaring

120. flood

121. flutter kick

122. fronds

123. Gay-Lussac’s law

124. gyres

125. half-time

126. heat exhaustion

127. heatstroke

128. Henry’s law

129. hypoventilation

130. ingassing

131. jumpsuit

132. J-valve

133. K-valve

134. lubber line

135. mediastinal emphysema

136. nitrogen narcosis

137. nitrox

138. no-decompression-stop limits

139. octopus

140. open-circuit

141. open-valve-ascent

142. outgassing

143. overturn

144. perfusion

145. pnemothorax

146. pony tank

147. ports

148. pulmonary barotrauma

149. repetitive group

150. residual nitrogen

151. residual nitrogen time

152. rest stop

153. reverse block

154. rip current

155. sawtooth dive profile

156. scissor kick

157. scombroid

158. SCUBA

159. set

160. sink

161. siphon

162. skip breathing

163. slack water

164. spare air unit

165. spike dives

166. spring tides

167. squeeze

168. stages

169. stand

170. stipes

171. subcutaneous emphysema

172. submersible pressure gauge

173. surf

174. surface interval time

175. surge

176. swells

177. tetrodotoxin

178. total bottom time

179. Tonybee maneuver

180. trapdoor effect

181. trough

182. tsunami

183. turbid

184. Valsalva maneuver

185. valve seat

186. vasoconstriction

187. vertigo

188. wave height

189. wave period

190. wavelength

191. An object us neutrally buoyant when it displaces an amount of water less than its own weight.

192. Buoyancy control is one of the most important skills at the surface and under water because _____.

193. The same object would be more buoyant in _____ than it would be in _____.

194. Because water is denser then air the pressure change for a given distance ascent or descent is significantly greater in water than in air.

195. What is a squeeze?

196. How to equalize?

197. How often should you equalize?

198. If you feel discomfort in your ears while descending, continue downward until the discomfort is gone.

199. What is a reverse block?

200. What should you do if your feel discomfort during an ascent due to expansion?

201. Why must your nose be enclosed by your mask?

202. How to prevent water from your scuba cylinder?

203. The most important feature when purchasing a regulator is _____.

204. Underwater objects appear_____ making them seem _____ and _____.

205. Since it travels 4x faster in water than in air you will have difficulty determining the origin of _____ underwater.

206. Water conducts heat away from your body _____ than air does.

207. What should you do if you begin shivering underwater?

208. The procedures for the resistance of water.

209. Proper breathing pattern for diving.

210. How to prevent overexertion.

211. What do you do if you become overexerted under water?

212. What do you do if you become overexerted at the surface?

213. Techniques for airway control.

214. Why is it important to NOT wear a tight fitting hood?

215. The most important feature of any weight system is _____.

216. An alternate air source should be _____.

217. Where should you attach an alternate air source?

218. A diving knife is used as a tool but it is not intended to be used as a weapon.

219. How to check for proper buoyancy?

220. The steps of the pre-dive safety check.

221. What effects visibility under water?

222. To avoid problems associated with diving in clear water you should.

223. What do you do if you are caught in a current?

224. If a current is present you should _____.

225. Nearly all injuries form aquatic life are caused by _____ action on the part of the animal.

226. What should you do if you spot an aggressive animal underwater?

227. For safety and enjoyment when diving in a new area or engaging in a new activity, be sure to obtain a proper orientation.

228. A rip current can be recognized as a ling of turbid foamy water moving _____.

229. What are three ways to prevent diving problems?

230. The first step in assisting another diver with a problem is to talk to him, offering encouragement and persuading him to relax.

231. When should you do a buoyant emergency ascent?

232. When should you do a controlled emergency swimming ascent?

233. When should you do a alternate air source ascent?

234. If you become entangled underwater you should.

235. With an unconscious diver the primary concern is to remove him from the water.

236. Once removed from the water an unconscious breathing diver should be given oxygen.

237. An object is neutrally buoyant when it displaces an amount of water less than its own weight.

238. The same object would be more buoyant in _____ than it would be in _____."

239. Because water is denser than air, the pressure change for a given distance ascent or descent is significantly greater in water than in air. _____.

240. State the most important rule in scuba diving.

241. What are five uses for a surface float?

242. What do you do to avoid entanglement in a line connected to a surface float?

243. Why should you use a dive flag when diving?

244. How close should you stay to a dive flag and how far should boats, skiers and water craft stay away if there are no local laws gov. these distances?

245. You might need to take a diving light during the day for what do reasons?

246. What should you do for a diver suspected of breathing contaminated air?

247. How do you prevent nitrogen narcosis?

248. What condition occurs when a diver exceeds established depth and time limits producing bubbles in the body during and following ascent?

249. What is the primary use of dive tables and dive computers?

250. What are meant be no decompression/no-stop diving and decompression diving?

251. What is a "no decompression limit"?

252. What is bottom time?

253. What is the maximum depth limit for all recreational diving?

254. What is a pressure group?

255. What is a surface interval?


1. 1) temperature, 2) visibility, 3) water movement, 4) bottom composition, 5) aquatic life, and 6) sunlight

2. An abrupt change to a layer of colder water

3. Going deeper.

4. Push you parallel to the shore.

5. Foamy water, strong flow away from shore, and disruption of waves.

6. Swim parallel to shore.

7. Excellent.

8. Causing currents and affecting visibility.

9. High tide.

10. 1) Establish ample buoyancy, 2) Calm diver, 3) Help diver reestablish breathing control, 4) Assist diver back to short or boat

11. If you are on a boat, throw them something with a rope on it so you can pull them aboard. If they aren’t breathing, perform CPR, and if you don’t know it, yell for help or call someone.

12. checking for breathing, and begin rescue breaths if not breathing.

13. bring the diver to the surface and check for breathing

14. Do the same as if the diver looses consciousness, unless if they don’t loose consciousness, keep them on their side

15. Slowly, if you go too quickly then you may lose control of your buoyancy

16. push off masks and spit out regulators

17. Establish positive buoyancy and ask for help.

18. Bathroom on a boat

19. Front of the boat

20. Try your alternate site, and if it is bad, cancel the dive

21. passive, active

22. diver carelessness

23. Watch it, leave the area calmly

24. To help assure future populations of game animals

25. 1) wear an exposure suit and gloves, 2) what where you put your hands, feet and knees, 3) don’t touch anything you don’t recognize

26. 1) Remain neutrally buoyant, 2) Swim with your feet up off the bottom

27. 1) silt, 2) mud, 3) sand, 4) coral, 5) vegetation, 6) rock

28. waves, wind, tides

29. swimming against the current

30. the approximate distance you can see horizontally

31. 1) water movement, 2) suspended particles, 3) bottom composition

32. 1) buddy separation, 2) disorientation, 3) loss of direction

33. line, other reference

34. cooler

35. Choose your exposure protection based on the temperature at depth

36. an object neither sinks nor floats

37. an object floats

38. an object sinks

39. salt water

40. more

41. Never hold your breath

42. Your lungs could over-expand, which causes paralysis or death

43. It lets you control where you are in the water

44. BCD and lead weights

45. When you exhale and there is less air in your lungs, you become less buoyant.

46. lungs, sinuses, ears

47. mask, wet or dry suit

48. Because the rest of your body is mostly liquid, but air changes volume with pressure changes.

49. Because water weighs more than air.

50. Water pressure increases as you go deeper and decreases when you come back up.

51. When you double the pressure you halve the volume. When you triple the pressure you have one third of the volume.

52. Exhale into it through your nose

53. Keeping the air space pressure equal to the water pressure outside to avoid discomfort.

54. a squeeze

55. pinch your nose and blow gently with your mouth closed, swallow, wiggle your jaw from side to side

56. Discontinue (stop) the dive

57. Ascend until the discomfort goes away, equalize and continue a slow descent.

58. practicality, safety and fun

59. larger and/or closer

60. Because water absorbs light

61. seem to come from directly overhead

62. 20

63. end the dive immediately, dry off and seek warmth

64. When your body cools so much it can’t function normally.

65. slowly and smoothly, relaxed

66. slowly and deeply

67. A way to avoid accidentally getting water into your throat

68. 1) weight belt, 2) integrated weight system

69. quick release

70. You will float at eye level with an empty BCD and holding a normal breath

71. A second stage you may use to ascend while breathing normally

72. So it can be located easily

73. A tool

74. A weapon

75. total pressure exerted on a diver. atmospheric + gauge

76. time when a diver leaves the surface in descent until begins a rest stop or surfaces

77. surrounding pressure

78. the force of buoyancy acting on an object is equal to the weight of water displaced

79. embolism from an air bubble blocking arterial circulation

80. injury from pressure

81. decompression illness

82. indicate time or direction

83. on a submersible pressure gauge, to relieve pressure in the housing in case of a high-pressure leak

84. type of depth gauge that uses a thin metal tube in a spiral. movement of the coil linked to a needle indicates pressure exerted on the gauge

85. for any gas at constant temp, volume varies inversely with absolute pressure, density varies directly

86. thin metal disk, with over pressure the disk will burst, and the tank will went to avoid an explosion

87. type of depth gauge made up of a hollow, air filled, transparent plastic tube sealed at one end and placed around a circular dial, position of air-water interface changes with pressure

88. room like opening in a natural formation where light from the surface can be seen

89. openings with no light

90. certification card

91. minimum depth a diver cannot rise above without the risk of DCS

92. fish poisoning from a fish eating a certain species of algae

93. scuba system that eliminates carbon dioxide from exhaled breath and resupplies oxygen without allowing gases to escape from the system

94. mathematical models used to estimate gas absorption and elimination by various areas of the body

95. series of headings that lead to a destination

96. direction set on a compass

97. display unit that combines several instruments. attaches to the high pressure hose coming from the regulator first stage

98. address possible changes that may occur in a dive

99. area of the body that control how long a diver can stay at a given depth. made from how quickly gas diffuses from that compartment

100. states the total pressure exerted by a mixture of gases is the sum of the pressures that would be exerted by each gas if it was present alone and occupied the total volume

101. DCI. neurological symptoms on surfacing. the bends

102. precautionary stops made during an ascent in order to reduce risk of DCI

103. removing film of oil on goggles

104. threaded outlet for a scuba tank valve that has a recessed o-ring seal and withstands higher pressures

105. diagrams to plan a dive by plotting time and depth

106. evaluation to learn buoyancy control. weighted properly, a full inhalation will raise the shoulders while fin tips remain on the bottom. exhaling will drop shoulders

107. compensating downward current when wind blows along a coast with a steep drop off near shore

108. speed of the current

109. thin membrane separates ear canal from middle ear and transmits vibrations to inner ear via small bones

110. flow of water away from an area due to low tide

111. swirling currents from non linear water flow

112. blockage of circulation

113. required delay in ascent if the actual or total bottom time exceeds the no decompression stop limit for a dive

114. process of keeping the pressure inside an air space in or around the body equal to the ambient pressure

115. part of the ear that allows equalization of the middle ear

116. type of wet suit where leg material extends to chest with shoulder straps

117. area where waves are created

118. the distance wind travels unobstructed

119. method of slowing an uncontrolled ascent by arching the back, extending the arms and legs, and positioning the fins so the are parallel to the surface

120. flow due to high tide

121. most common. up and down

122. kelp leaves

123. any gas at a constant volume, pressure varies directly with absolute temperature

124. large circulating currents. clockwise in northern. CC in southern hemisphere.

125. time for a tissue to accumulate half of the gas it can hold at a given pressure

126. high core temperature and dehydration

127. body’s regulating temperature ability shuts down

128. the amount of gas that dissolves in a liquid at a given temp is directly proportional to the partial pressure of that gas

129. rapid and shallow breathing, doesn’t allow you to expel carbon dioxide

130. gas diffusion into a liquid

131. one piece

132. cylinder valve designed to maintain a reserve of air to permit normal ascent.

133. simple on - off. CC to open

134. reference line on a compass that indicates direction

135. lung injury where air is present in the tissues in the middle of the chest

136. detrimental effect caused by increased pressure of nitrogen at a depth of about 100 ft

137. nitrogen and oxygen mixture with higher percentage of oxygen than air. reduces the effects of nitrogen at depth

138. max time a diver can stay at a given depth

139. extra second stage

140. scuba system that permits a diver to breath compressed air from a pressurized cylinder and exhausts the gases into the water. safest and most popular

141. maintain neutral buoyancy by keeping the BC inflator-deflator valve open while holding the valve in a special way

142. gas diffusing out of a liquid. diffusing of nitrogen absorbed under pressure

143. water circulation from wind that moves oxygenated water to about 60 ft - spring diving conditions

144. circulation in a tissue

145. lung injury where air is trapped in the lungs

146. back up tank with its own regulator

147. openings in the first stage of a regulator. one for high pressure air measurement with an SPG. others for low pressure

148. lung injury caused by pressure

149. letter that designates the amount of nitrogen in a divers body

150. nitrogen that remains within the past 12 hours

151. amount of time added to actual bottom time of a repetitive dive to determine the totale bottom time. compensates for residual nitrogen

152. precautionary decompression stop during ascent

153. discomfort that occurs when the pressure in the middle ear is above normal during ascent due to blockage of the eustachian tube

154. narrow strong current that moves away from shore as a result of water flowing back to sea through a narrow opening in an underwater obstruction

155. deep to shallow to deep

156. laying on your side

157. fish poisoning from not chilling

158. self contained underwater breathing apparatus

159. direction assumed by a current

160. underwater cavity from the ground collapsing

161. an opening where water is channeled from a sink back to the system

162. holding breath between breaths

163. between flow and ebb with minimal water movement

164. backup tank with a special regulator integrated directly into the valve. smaller than a pony

165. dive with short actual bottom time

166. highest tides

167. condition that occurs when the pressure on the outside of an airspace is greater than the inside pressure. may cause pain

168. two parts of a scuba regulator for pressure reduction

169. tide neither falls or rises

170. long strand of kelp

171. lung injury in which air is present in the tissues under the skin. swells the tissue around the neck

172. measures scuba cylinder pressure

173. breaking waves that occur when the water withing the eave moves forward and gives up its energy. when the depth is about the same as the wave height

174. the elapsed time from when a divers surfaces to the time the diver begins a repetitive dive

175. back and forth subsurface motion of water within waves when waves enter shallow water

176. rounded, undulating forms that waves take as they move away from the area they were created

177. fish poisoning from exotic fish

178. actual bottom time + residual nitrogen time

179. opening the eustachian tubes by blocking the nostrils, closing the mouth, and swallowing

180. condition when pressure prevents the eustachian tube from opening. overcome by ascending to reduce pressure

181. bottom of a wave. crest is the top

182. gigantic seismic waves caused by underwater earthquake

183. unclear water from stirred up sediment

184. opening the euastchian tubes by blocking the nostrils, closing the mouth, and gently trying to exhale

185. portion of the cylinder valve that closes and stops the flow of air

186. narrowing of blood vessels

187. subjective feeling of movement perceived as a spinning sensation

188. distance from crest to trough

189. time for 2 waves to pass a certain point

190. distance between waves

191. FALSE

192. it lets you control where you are in the water

193. saltwater, freshwater

194. TRUE

195. a condition that causes pain and discomfort when the pressure group inside an air space of your body is less then the pressure group outside an airspace

196. plug your nose and blow out, swallow and wiggle the jaw, and do both

197. every few feet before discomfort

198. FALSE

199. a condition that occurs when expanding air cannot escape from a body air space during ascent, causing pain ad comfort

200. stop or slow descent, and give the trapped air time to work its way out

201. so you can equalize it

202. never let the cylinder empty completely

203. ease of breathing

204. magnified, larger, closer

205. sound

206. faster

207. get out of the water, change clothes, and get warm, and dry off

208. streamline yourself and your equipment, avoid jerky movements, move slowly, pace yourself, and have proper weight

209. consistently slow and deep

210. move slowly and avoid extended strenuous activity, and know your limits

211. stop all activity, breathe deeply, and rest

212. establish buoyancy and stop moving

213. use your tongue as a splash guard, exhale slowly, and inhale cautiously

214. it can constrict blood flow through the head and can cause light headiness

215. a quick release mechanism

216. conspicuously marked

217. to your chest

218. TRUE

219. float at eye level with an empty bdc and holding a normal breath

220. BWRAF: bcd, weights, releases, air, final okay

221. weather, water movement, and suspended particles

222. use an accurat depth gauge, refer to it often, and use a line for ascents and descents

223. fill you bcd, drop your weights, signal for help, and wait for the boat to pick you up

224. begin you dive against the current

225. defensive

226. watch it and leave the area calmly on the bottom if it remains or appears aggressive

227. TRUE

228. seaward

229. establish buoyancy, dive within your limits, and relax while you dive

230. FALSE

231. when your buddy is far away and you are deeper then 30 feet

232. when your buddy is far away and you are no deeper than 30 feet

233. when your buddy is near

234. stop think and work yourself out of it

235. FALSE

236. TRUE

237. FALSE

238. saltwater, freshwater

239. TRUE

240. Never hold your breathe.

241. Resting, Marking a dive site, Assisting another diver, Carrying things, Supporting a dive flag

242. Carry the line on a reel or line caddy to avoid entanglement

243. For safety when boat traffic is around, you need to use a dive flag

244. Boats must stay 30/60 meters away from flag.

245. Dive lights are handy to restore color to what you are looking at, at deep depths.

246. End the dive immediately, save bad air for analysis.

247. Simply avoid deep dives

248. Decompression Sickness

249. To track the theoretical nitrogen you have in your body before, during and after diving.

250. You’ll always plan your dives so that you can always ascend directly to the surface without stopping, yet without significant risk of decompression sickness.

251. This is the absolute deepest you would be allowed to go for a certain amount of time.

252. In repetitive diving the total time actually spent under water from beginning of descent until leaving the bottom for a direct ascent.

253. 40m/130ft.

254. A letter used on the Recreational dive planner to designate the amount of theoretical residual nitrogen in your body.

255. The Amount of time spent on the surface between two dives. It is usually recorded in hours and minutes.


Disco - 9/18/2013 4:29 PM
Awesome. I’m sure will help me with the PADI DM test I have coming up.
Greg - 9/19/2013 6:20 AM
good luck!
Eric_R - 8/08/2013 7:02 PM
Did you make your wife type all of those.LOL
Greg - 8/09/2013 4:45 AM
Nope, found them online and just cleaned them up a bit.