Diving at Altitude
I am the medical officer for Peace Corps Jordan. While I am not a diver, many Peace Corps volunteers and staff dive in Aqaba, in the Red Sea, at the southernmost point of the country. Because of the difference in elevation between Aqaba and Amman, divers are advised to spend the night in Aqaba in order to avoid the bends. One of our volunteers is living in a village at the southernmost end of the Dead Sea, at approximately 365 meters / 1,197 feet below sea level. This young man is 29 years old, a diver, and in good health. My questions are:
1. What are the long-term side effects of living for a prolonged period (two years) at approximately 1,200 feet below sea level?
2. Would this person need to take any precautions before diving in the Red Sea in Aqaba?
3. If he would need to be transported via medevac for any reason from Jordan, would he not be able to fly within a specific period?
1. What are the long-term side effects of living for a prolonged period (two years) at approximately 1,200 feet below sea level?
2. Would this person need to take any precautions before diving in the Red Sea in Aqaba?
3. If he would need to be transported via medevac for any reason from Jordan, would he not be able to fly within a specific period?
- There is no evidence that living at depth, at least at such a small water-equivalent depth, has any deleterious effects. The barometric pressure at the surface of the Dead Sea is about 800mmHg (normal atmospheric pressure is 760mmHg). Prolonged subsea living, such as experienced by those divers exposed to saturation dives in underwater habitats (e.g., Tektite II at 50 feet/15 meters, or 1,150 mmHg), may have numerous side effects, ranging from decompression illness to dysbaric osteonecrosis (the death of portions of the long bones in the body in a proportion of those exposed to increased pressure). The dangers of Dead Sea living come more from exposure to the sun and the extreme salinity of the water.
- The young man should consider himself to be diving at altitude in the Red Sea in Aqaba (when coming from his subsea home); this is a theoretical answer to the question as there is no data to support the following proposition. Standard tables were designed for sea-level dives only. The Theoretical Ocean Depth (TOD) concept was suggested by NOAA (National Oceanographic and Atmospheric Administration) to cope with diving at altitude. NOAA looked at the difference in barometric pressures at various altitudes and recalculated the dive tables based upon the new equivalent water depth, both for fresh water and sea water. This calculation converted for the Dead Sea would add about three feet (one meter) to any given dive. This in turn means he should count each dive as being one stop deeper. The U.S. Navy tables recommend, in fact, that no alteration be made for dives at altitudes lower than 2,300 feet / 701 meters. A few dive computers use the Buhlmann correction for altitude, using the same principle as the TOD. Unfortunately, as they assume a sea-level starting point they would make an incorrect assumption for this diver.
- DAN's preliminary research findings indicate that waiting to fly or go to elevation after diving requires at least a 12-hour wait after a single no-stop dive and a wait for an extended surface interval beyond 12 hours after multiple dives in a single day before flying. If the diver developed symptoms of decompression illness and required a medical evacuation, there should be no problem if the plane could pressurize the cabin to 800mmHg. In a dire situation in which the diver requires transportation over a mountain pass or other elevation to reach a medevac aircraft, then he should breathe 100 percent oxygen during the trip to prevent or lessen any effect that altitude may have on symptoms of decompression illness.
Posted in Dive Safety FAQ
Categories
2021
March
Old Habits Die HardSave a Diver, Save YourselfCylinder SafetyUndercover CrabsReef safe sunscreenPhysics, Biophysics and Decompression SicknessModels and Marine LifeSunscreen and CoralCristina Mittermeier: Commitment to ConservationDiving After a StrokeCurrent DivesThis Bites: Prevention TreatmentEnvironmental Considerations for Disinfection
April
Aqua Pool Noodle ExercisesUnderwater Photographer and DAN Member Madelein Wolfaardt10 Simple Things You Can Do to Improve Your Underwater PhotographyCOVID-19 and Diving: March 2021 UpdateDiver Return After COVID-19 Infection (DRACO): A Longitudinal AssessmentGuidelines for Lifelong Medical Fitness to Dive
2020
January
February
Group Fitness at the PoolHow to Rescue a Distressed diver at the SurfaceHow to manage Near-DrowningNo Sit-ups no problem How to manage MalariaHow to manage Oxygen Deficiency (Hypoxia)What to do when confronted by a sharkHow to manage Scombroid PoisoningHow to perform a Deep Diver RescueHow to perform One-rescuer CPRHow to perform a Neurological Assessment
March
DAN’s Quick Guide to Properly Disinfecting Dive GearCOVID-19 : Prevention Recommendations for our Diving CommunityGermophobia? - Just give it a reasonable thoughtScuba Equipment care – Rinsing and cleaning diving equipmentCOVID-19 and DAN MembershipFurther limitations imposed on travels and considerations on diving activitiesDAN Membership COVID-19 FAQsLancet COVID-19 South African Testing SitesCOVID-19 No Panic Help GuideGetting Decompression Sickness while FreedivingDown in the DumpsCardiovascular Disease and DivingDelayed Off-GassingDiving after Dental surgeryDiving with Multiple MedicationsPygmy Seahorses: Life AquaticAfrica DustCOVID-19 Myth BustersScuba Units Are Not Suitable Substitutes for VentilatorsDisinfection of Scuba Equipment and COVID-19Physioball Stability Exercises
April
COVID-19 AdvisoryScuba Equipment Care - Drying & Storing Your GearTransporting Diving Lights & BatteriesHow to Pivot Your Message During a CrisisTourism Relief FundCOVID-19 Business Support ReviewDiving After COVID-19: What We Know TodayEUBS-ECHM Position Statement on Diving ActivitiesPart 2: COVID-19 Business Support ReviewPress Release
May
Diving in the Era of COVID-19Dive Operations and COVID-19: Prepping for ReturnCOVID-19 & Diving Activities: 10 Safety RecommendationsCOVID-19: Surface Survival TimesThe Philippines at its FinestThe Logistics of ExplorationThe Art of the Underwater SelfieShooter: Douglas SeifertFAQs Answered: Disinfecting Scuba EquipmentStock your First-Aid KitResearch and OutreachCovid-19 ResearchOut of the BlueEffects of Aspirin on DivingThe New Pointy end of DivingDiving and Hepatitis CCaissons, Compressed-Air work and Deep TunnellingPreparing to Dive in the New NormalNew Health Declaration Form Sample Addressing C-19 IssuesDiving After COVID 19: What Divers Need to Know
June
Travel Smarter: PRE-TRIP VACCINATIONSAttention-Deficit/Hyperactivity Disorder and DivingCOVID-19: Updated First Aid Training Recommendations From DANDiving with a Purpose in National Marine SanctuariesStay Positive Through the PandemicFor the Dive Operator: How to Protect Your Staff & ClientsStudying Deep reefs and Deep diversAsking the Right QuestionsLung squeeze under cold diving conditions
July
Dive DeprivationVolunteer Fish Surveys: Engage DiversDAN Member Profile: Mehgan Heaney-GrierTravel Smarter: Don’t Cancel, Reschedule InsteadDive Boat Fire SafetyRay of HopePartner ExercisesDiving at AltitudeAluminium ExposureHip FracturesAcoustic NeuromaGuidelines for Lifelong Medical Fitness to DiveNew Dive Medical Forms
August
Women in Diving: Lauren Arthur, Conservationist & Natural History Story TellerWomen in Diving: Dr Sara Andreotti White Shark ResearcherTiming ExerciseWomen in Diving: The Salty Wanderer, Charlie WarlandWomen in Diving: Beth Neale, Aqua soul of freedivingWomen in Diving: Diving and spearfishing Diva, Jean HattinghWomen in Diving: Zandile Ndhlovu, The Black Mermaid
September
October
Freediving For ScienceStep Exercises with CardioFluorescence Imaging help Identify Coral BleachingChildren and DivingThe Watchman device and divingScuba Diving and Factor V Leiden gene mutationNitrogen Narcosis at shallow depthsOil and Particulates: Safe levels in Breathing Air at depthDive Principles for Coping with COVID-19The Importance of a Predive Safety CheckTalya Davidoff: the 'Plattelandse Meisie' Freediver
2019
February
April
May
DAN Press ReleaseYour Dive Computer: Tips and tricks - PART 1Your Dive Computer: Tips and tricks - PART 2Aural HygieneDCS AheadHow Divers Can Help with coral conservationRed Tide and shellfish poisoningDiving after Kidney DonationDiving with hypertrophic cardiomyopathyEmergency Underwater Oxygen Recompression
June
July
September
October
November
Exercise drills with DowelsHeart-rate TrainingCultivating ConservationTRavel Smarter : Evaluating an unfamiliar Dive operatorChallenging the Frontiers of Decompression ResearchTravel Smarter: Plan for Medical EmergenciesWhen should I call my Doctor?DAN Student Medical Expense CoverageAdvice, Support and a LifelineWetsuits and heat stressDiving after Chiropractic adjustments
2018
April
Flying after pool diving FAQLung squeeze while freediving FAQDiving after Bariatric surgery FAQMarine injuries FAQVasovagal Syncope unpredictable FAQIncident report procedure FAQDiving after knee surgery FAQDiving when in RemissionDive with orbital Implant FAQInert gas washout FAQOxygen ears FAQPost Decompression sicknessChildren and diving. The real concerns.Diving after SurgeryPhysiology of Decompresssion sickness FAQDiving and regular exerciseGordon Hiles - I am an Underwater Cameraman and Film MakerScuba Air QualityBreath-hold diving. Part 3: The Science Bit!Compensation Legislation and the Recreational DiverCape Town DivingFive pro tips for capturing better images in cold waterThe Boat Left Without You: Now What?
May
When things go wrongEmergency Planning: Why Do We Need It?Breath-hold diving: Running on reserve -Part 5 Learning to RebreatheSweet Dreams: When Can I Resume Diving Post Anaesthesia?Investing in the future of reefsTo lie or not to lie?THE STORY OF A RASH AFTER A DIVEFirst Aid KitsTaravana: Fact or Falacy?
June
Oxygen Unit MaintenanceKnow Your Oxygen-Delivery Masks 1Know Your Oxygen-Delivery Masks 2Emergency Oxygen unitsInjuries due to exposure - HypothermiaInjuries due to exposure - Altitude sicknessInjuries due to Exposure - Dehydration and other concernsHow to plan for your dive tripThe Future of Dive MedicinePlastic is Killing our ocean
September
Return to DivingDiagnoses: Pulmonary blebSide effects of Rectogesic ointmentDiving with ChemotherapyReplacing dive computers and BCDsCustomize Your First-Aid KitPlan for medical emergenciesHow the dive Reflex protects the brain and heartDry suits and skin BendsAltitude sickness and DCSScuba Diving and Life Expectancy
2017
March
April
Incident Insight: TriageA Field Guide to Minor MishapsSnorkels: Pros & ConsTime & RecoveryMedication & Drug UseDiving with CancerNitrox FAQCOPD FAQHyperbaric Chamber FAQJet Lag FAQHydration FAQAnticoagulant Medication FAQFluid in the Ear FAQEye Surgery FAQElderly Divers FAQNitrogen FAQHealth Concerns FAQMotion Sickness FAQMicronuclei FAQ
June
August
2016
February
March
Breath-Hold Diving & ScubaReturn to Diving After DCITiming Exercise & DivingHot Tubs After DivingSubcutaneous EmphysemaIn-Water RecompressionDiving at AltitudeFlying After DivingDiving After FlyingThe Risks of Diabetes & DivingFlu-like Symptoms Following a DiveHand & Foot EdemaFrontal HeadachesBladder DiscomfortLatex AllergiesRemember to BreatheProper Position for Emergency CareAches & PainsCell Phones While DrivingSurfers Ear Ear Ventilation TubesDealing with Ear ProblemsDiving with Existing Ear InjuriesPerforated Ear DrumENT SurgeryUnpluggedCochlear ImplantsPortuguese Man-of-WarJellyfish StingsLionfish, Scorpionfish & Stonefish EnvenomationsStingray Envenomation Coral Cuts, Scrapes and RashesSpeeding & Driving Behaviour
June
Newsflash! Low Pressure Hose DeteriorationItching & rash go away & come back!7 Things we did not know about the oceanMigraine HeadacheAttention Deficit Disorder Cerebral Vascular AccidentEpilepsyCerebral PalsyHistory of SeizuresMultiple Sclerosis Head TraumaBreast Cancer & Fitness to Dive IssuesLocal Allergic ReactionsSea LiceHow ocean pollution affects humans Dive Fatality & Lobster Mini-Season StatisticsPregnancy & DivingReturn to Diving After Giving BirthBreast Implants & DivingMenstruation During Diving ActivitiesOral Birth ControlBreast FeedingPremenstrual SyndromeOsteoporosisThe Aftermath of Diving IncidentsCompensation Legislation & the Recreational DiverNoise-Induced Hearing LossLegal MattersThe Nature of Liability & DivingDAN Legal NetworkWaivers, Children & Solo DivingHealthy, but overweight!Taking Medication while Scuba DivingGetting Fit for the Dive SeasonBone Considerations in Young DiversAsthma and Scuba DivingHepatitisDiving with HyperglycemiaShoulder PainDiving After Spinal Back Surgery
August
Hazard Identification & Risk AssessmentCaring For Your People Caring For Your FacilitiesCaring For Your BusinessScuba Air Quality Part 1Scuba Air Quality Part 2Chamber Maintenance Part 1Chamber Maintenance Part 2The Aging Diver Propeller SafetyRelease The PressureDon't Get LostMore Water, Less Bubbles13 Ways to Run Out of Air & How Not To7 Mistakes Divers Make & How To Avoid ThemSafety Is In The AirHow Good Is Your Emergency Plan
2015
January
March
No Comments