UHMS/NOAA DIVING PHYSICIANS COURSE US NAVY AIR DECOMPRESSION TABLES REVIEW Note: Use USN Tables 9-7, 9-8, and 9-9 for all questions. Question #1: You have just completed a dive to 130 fsw (40 msw) for 20 minutes. You are on the surface for 2 hours and want to make a repetitive dive to 100 fsw (30.5 msw) for 20 minutes. What will be the ending RGD following the second dive? If decompression is required, use inwater air decompression all the way to the surface. Answer #1: RGD N I 2:00 G N 20 ---- :04 20 ---- :36 130 100 130/:20 100 /:45 :20 ABT :23 RNT RNT + :20 ABT :43 ESDT 1
Question #2: Following a dive to 95 feet (29 msw) for 28 minutes and a surface interval of 3 hours, what is the deepest depth to which a diver may dive for at least 30 minutes with no required decompression? If decompression is required on the first dive, use in-water air/o 2 decompression all the way to the surface. Answer #2: 55 FSW (16.8 MSW) J 3:00 G L 20 ---- :02 95 100 /:30 55 55 /:74 :28 ABT :44 RNT RNT + :30 ABT :74 ESDT 2
Question #3: You want to conduct a fourth dive of the day at 75 fsw (22.9 msw) for 10 minutes. Prior to this dive, you completed three dives to 75 fsw (22.9 msw) for 11, 12, and 13 minutes respectfully. All three dives were made very close together (i.e. < 10 minutes apart) and you did not keep any surface interval times. Can the fourth dive be conducted without decompression following a SIT of <10 minutes from the previous dive? If not, what would be the RGD following the fourth dive assuming in-water air decompression is used all the way to the surface. ABT RNT RNT RNT ABT ABT ABT ESDT ESDT ESDT Answer #3: No; M RGD M 20 ---- :17 75 75 75 75 80 /:50 :11 ABT :11 RNT :23 RN :36 RNT + :12 ABT + :13 AB + :10 ABT :23 ESDT :36 ESDT :46 ESDT 3
Question #4: You make a dive to 75 fsw (22.9 msw) for 20 minutes. After 08 minutes on the surface, you make another dive to the same depth for 20 additional minutes. What would be the RGD at the end of the second dive assuming in-water air/o2 decompression is used all the way to the surface? Answer #4: J RGD :08 J 75 75 80 /:40 20 ---- :01 (on O 2 ) :20 ABT :20 RNT RNT + :20 ABT + ABT :40 ESDT ESDT 4
Question #5: You wish to complete the three dives listed below. What is the minimum surface interval between dive #1 and dive #2 in order for the second dive to be conducted without decompression? Following a 2-hour SIT, the third dive is conducted. How much decompression is required assuming in-water air decompression is performed all the way to the surface? Dive #1 depth = 90 fsw (29 msw), actual bottom time = :22 minutes Dive #2 depth = 80 fsw (24.4 msw), actual bottom time = :15 minutes Dive #3 depth = 60 fsw (18.3 msw), actual bottom time = :30 minutes ESDT Answer #5: 1:45 SIT & :14 minutes G 1:45 E J 2:00 H N 20 ---- :14 90 90 /:24 80 80 /:39 60 60 /:80 :22 ABT :22 RNT :46 RNT + :15 ABT + :30 ABT :37 ESDT :76 ESDT 5
Question #6: You make a dive to 73 fsw (22.3 msw) for 37 minutes. During ascent, you develop a reverse ear block at a depth of 65 fsw (19.8 msw) and it takes 05 minutes at that depth to clear your ears and continue ascent. Is staged decompression required for this dive? If so, what would be the RGD following the dive assuming in-water air/o 2 decompression is conducted? ESDT Answer #6: Yes; K RGD K 20 :05 (on O 2 ) 73 80 /:45 65 :05 :37 ABT RNT RNT + :05 + ABT :42 ESDT 6
Question #7: You and your dive buddy make a dive to 125 fsw (38.1 msw) for 09 minutes with a safety stop at 15 fsw (4.6 msw) for :04 minutes. After 2½ hours on the surface, you make a repetitive dive to 95 fsw (29 msw) for 15 minutes, with another safety stop at 15 fsw (4.6 msw) for 04 minutes. After 30 minutes on the surface, you want to make a third dive to 75 fsw (22.9 msw) for15 minutes. Can the third dive be conducted within the no-decompression limits? ESDT Answer #7: No; :17 minutes deco on air or :09 on O 2 D 2:30 B H :30 H M 15 :04 15 :04 20 --- :17 :09 125 130 /:09 95 100 /:25 75 80 /:50 :09 ABT :08 RNT :33 RNT + :15 ABT + :15 ABT :23 ESDT :48 ESDT 7
Question #8: You have completed a dive to 125 fsw (38.1 msw) for 16 minutes. Following a surface interval of 2½ hour, you wish to dive to 55 fsw (16.8 msw) for 35 minutes without having to decompress. Can the repetitive dive be made without decompression? ESDT Answer #8: No I 2:30 G M 20 :04 (on air) or 20 ---- :04 (on air) or :02 (on O 2 ) :02 (on O 2 ) 125 130 /:20 55 55 /:80 :16 ABT :44 RNT RNT + :35 ABT :79 ESDT 8
Question #9: A diver makes a no-decompression dive to 85 fsw (26 msw) for 12 minutes. Following a SIT of 1:00, the diver makes another dive to 65 fsw (19.8 msw) for as long as possible staying within the no-decompression limit. Following a SIT of 2:00, the diver wants to make a third dive to 65 fsw (19.8 msw) for :30 minutes. Can the third dive be made as a nodecompression dive? ESDT Answer #9: No; requires :44 minutes decompression on air or :17 minutes on O 2 D 1:00 C K 2:00 I O 85 90 /:14 65 70 /:48 65 70 /:80 20 --- :44 :17 :12 ABT :16 RNT :44 RNT + :32 ABT :30 ABT :48 ESDT :74 ESDT 9
Question #10: A diver makes a sea-level dive to 70 fsw (21.4 msw) for the maximum nodecompression limit. Following a 2½ hour surface interval, the diver makes a second sea-level dive to 50 fsw (15.3 msw) for 35 minutes. What is the minimum time the diver must wait at the surface following the second dive before flying? Time to fly = ABT RNT Answer #10: 19 hours & 04 minutes K 2:30 I N Time to fly = 19:04 70 70 /:48 50 50 /:100 20 ---- :04 (on air) or :02 (on O 2 ) :48 ABT :65 RNT + :35 ABT :100 ESDT 10