Altitude and diving
I have been invited to a diving weekend on El Hierro, Spain. The accommodation where the divers are staying however is at about 1000 mt altitude. There will be 2-3 dives per day, varying depths, all well within limits. What the minimum surface interval should be before ascending to the accommodation?
Answer from DAN experts:
Be aware that a change of altitude post dive, in excess of approximately 700m is considered carrying the same risk as flying after diving. As your transition will be of 1000m then this applies to you. The most prudent is to leave 24 hours before flying or going to high altitude, but the minimum guidelines established by DAN and the Undersea and Hyperbaric Medical Society for flying/altitude (Sheffield and Vann 2004) are:
• A single dive within the no-decompression limits: 12 hours
• Repetitive dives or multiple days of diving: 18 hours
• Decompression dives (planned or unplanned): substantially greater than 18 hours.
This means that, with 2-3 dives a day you would be required to wait at least 18 hours. Since this seems impossible to do, you are strongly advised to either restrict your diving to a single dive daily, to permit yourself an adequate surface interval, or change accommodation.