Return to Diving



DANのホームページに掲載されていた、米国海軍の「Return to Diving」ポリシーを参考にしたガイドラインによると、

  1. Divers with uncomplicated, pain-only DCI cases and whose symptoms resolve completely after 10 minutes breathing oxygen at 60 feet / 18 meters can return to diving after 48 hours of being symptom-free.” This is probably a little too aggressive for recreational diving. Two to four symptom-free weeks is usually recommended for recreational divers.
  2. In uncomplicated pain-only DCI, divers who have had a completely normal neurological exam prior to recompression and whose symptoms took longer than 10 minutes to resolve, the Navy allows a two-week wait before a return to diving.” This may be too soon for recreational divers, who may return to multiday repetitive diving. A minimum wait of four weeks is a more conservative option.
  3. If divers have had cardiorespiratory or neurological symptoms such as weakness or numbness, the Navy recommends a four-week waiting period.” A six-week symptom-free minimum wait may be more appropriate for recreational divers.
  4. In more complicated DCI cases, in which symptoms seem to resist treatment or in which long treatment tables such as Table 4 or Table 7 are required, the Navy requires a minimum of a three-month layoff from diving. Diving may resume only after a thorough review by a Diving Medical Officer.” For recreational divers who experience DCI this severe, giving up diving altogether may be appropriate. At any rate, recreational divers should take a six-month hiatus from diving, followed by a thorough examination by a dive physician.

Wait until you have been free of symptoms for four weeks;
Seek evaluation by a physician to determine whether there is some predisposition to decompression illness.



  • 最低6ヶ月はダイビングをしてはダメ
  • 医師の助言を求めろ




U.S. Navy Diving Manual Volume 5


Tenders on Tables 5, 6, 6A, 1A, 2A, or 3 should have a minimum of a 12-hour surface interval before no-decompression diving and a minimum of a 24-hour surface interval before dives requiring decompression stops. Tenders on Tables 4, 7, and 8 should have a minimum of a 48-hour surface interval prior to diving.

21-6.1 Post-Treatment Observation Period. After a treatment, patients treated on a Treatment Table] 5 should remain at the recompression chamber facility for 2 hours. Patients who have been treated for Type II decompression sickness or who required a Treatment Table 6 for Type I symptoms and have had complete relief should remain at the recompression chamber facility for 6 hours. These times may be shortened upon the recommendation of a Diving Medical Officer, provided the patient will be with personnel who are experienced at recognizing recurrence of symptoms and can return to the recompression facility within 30 minutes. All patients should remain within 60 minutes of a recompression facility for 24 hours and should not be left alone during that period.

21-6.2 Post-Treatment Transfer. Patients with residual symptoms should be transferred to appropriate medical facilities as directed by qualified medical personnel. If ambulatory patients are sent home, they should always be accompanied by someone familiar with their condition who can return them to the recompression facility should the need arise. Patients completing treatment do not have to remain in the vicinity of the chamber if the Diving Medical Officer feels that transferring them to a medical facility immediately is in their best interest. CHAPTER 21 - Recompression Therapy Change A 21-29

21-6.3 Inside Tenders. Treatment table profiles place the inside tender(s) at risk for decompression sickness. After completing treatments, inside tenders should remain in the vicinity of the recompression chamber for 1 hour. If they were tending for Treatment Table 4, 7, or 8, inside tenders should also remain within 60 minutes of a recompression facility for 24 hours.

21-6.4 Flying After Treatments. Patients with residual symptoms should fly only with the concurrence of a Diving Medical Officer. Patients who have been treated for decompression sickness or arterial gas embolism and have complete relief should not fly for 72 hours after treatment, at a minimum.

21-6.4.1 Emergency Air Evacuation. Some patients will require air evacuation to another treatment or medical facility immediately after surfacing from a treatment. They will not meet surface interval requirements as described above. Such evacuation is done only on the recommendation of a Diving Medical Officer. Aircraft pressurized to one ata should be used if possible, or unpressurized aircraft flown as low as safely possible (no more than 1,000 feet is preferable). Have the patient breathe 100 percent oxygen during transport, if available.

21-6.4.2 Tender Surface Interval. Tenders on Tables 5, 6, 6A, 1A, 2A, or 3 should have a 24-hour surface interval before flying. Tenders on Tables 4, 7, and 8 should not fly for 72 hours.

21-6.5 Treatment of Residual Symptoms. After completion of the initial recompression treatment and after a surface interval sufficient to allow complete medical evaluation, additional recompression treatments may be instituted. For persistent Type II symptoms, daily treatment on Table 6 may be used, but twice-daily treatments on Treatment Tables 5 or 9 may also be used. The treatment table chosen for re-treatments must be based upon the patient’s medical condition and the potential for pulmonary oxygen toxicity. Patients surfacing from Treatment Table 6A with extensions, 4, 7, or 8 may have severe pulmonary oxygen toxicity and may find breathing 100 percent oxygen at 45 or 60 feet to be uncomfortable. In these cases, daily treatments at 33 feet may also be used. As many oxygen breathing periods (30 minutes on oxygen followed by 5 minutes on air) should be administered as can be tolerated by the patient. Ascent to the surface is at 20 feet per minute. A minimum oxygen breathing time is 90 minutes. A practical maximum bottom time is 3 to 4 hours at 33 feet. Treatments should not be administered on a daily basis for more than 5 days without a break of at least 1 day. These guidelines may have to be modified by the Diving Medical Officer to suit individual patient circumstances and tolerance to oxygen as measured by decrements in the patient’s vital capacity.

21-6.5.1 Additional Recompression Treatments. Additional recompression treatments are indicated as long as they are prescribed by a Diving Medical Officer. In treating residual symptoms, no response to recompression may occur on the first one or two treatments. In these cases, the Diving Medical Officer is the best judge as to the number of treatments. Consultation with NEDU or NDSTC may be appropriate (phone numbers are listed in paragraph 21-1.4). As the delay time between completion of initial treatment and the beginning of follow-up hyperbaric treatments increases, the probability of benefit from additional treatments decreases. However, improvement has been noted in patients who have had delay times of up to 1 week. Therefore, a long delay is not necessarily a reason to preclude followup treatments. Once residual symptoms respond to additional recompression treatments, such treatments should be continued until no further benefit is noted. In general, treatment may be discontinued if there is no further sustained improvement on two consecutive treatments.

21-6.6 Returning to Diving after Treatment Table 5. Divers who meet all of the criteria for treatment using Treatment Table 5, as outlined in paragraph 21-5.4.1 and who have had complete relief, may return to normal diving activity 7 days after surfacing from the Treatment Table 5. If there is any doubt about the presence or absence of Type II symptoms, the diver should be examined by a Diving Medical Officer before resumption of diving.

21-6.6.1 Returning to Diving After Treatment Table 6. Divers who had symptoms of arterial gas embolism, Type II DCS, or Type I DCS requiring a Treatment Table 6 should not dive for at least 4 weeks and should resume diving only upon the recommendation of a Diving Medical Officer.

21-6.6.2 Returning to Diving After Treatment Table 4 or 7. A diver having cardiorespiratory and/or CNS symptoms severe enough to warrant Treatment Table 4 or 7 should not dive for a minimum of 3 months, and not until a thorough review of his case by a Diving Medical Officer has established that return to normal diving activity can be accomplished safely.