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High Risk / Remote Presentation Ascension Island. Sub-Aqua Expeditions 2012. ‘Diving defensively, diving conservatively’. High Risk / Remote Presentation Ascension Island. Sub-Aqua Expeditions 2012
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High Risk / Remote Presentation Ascension Island Sub-Aqua Expeditions 2012 ‘Diving defensively, diving conservatively’
High Risk / Remote Presentation Ascension Island Sub-Aqua Expeditions 2012 ‘Developing individual courage and leadership skills through controlled exposure to risk in a challenging outdoor environment in order to enhance operational capability’ JSP 419
Scope • Ascension Island • Location, Orientation, Overview • Dive Sites • Value of Diving Ascension • Typical Expedition and Diving Conduct • Equipment • Hazards, Risks and Control Measures • DCI Risk
Location Canary Islands • 480 nm south of Equator • ~ 9 hr flight from UK • 810 nm SSW Liberia • 1200 nm Brazil (Recife) Dakar Ascension Island Brazil
Orientation English Bay & Jetty Expedition Centre • Georgetown • Lifeboat • Hospital • Travellers Hill • Accommodation • Messing • Airfield • Ops & Met Office • Medical Centre
Expedition Centre • Ablutions • Dormitories • Kitchen • Crewroom/classroom • Equipment store • Compressor area • BBQ / patio area
Dive Site Locations North Boatswain Bird Island / Rock Prevailing wind direction – 130o
Dive Sites Wall • Volcanic • Lava flow reefs, boulders • Gradual increase in depth • Most scenic sites: ~5-20m • Swim throughs • Gullies • Arches • Flattened wrecks: ~7-20m • 2 ‘wall’ sites - >30m+ Wall
Confined Water / ApprovedSwimming Areas Comfortless Cove SWTA English Bay
Value of Diving Ascension • Unique, varied environment & opportunity • Rich, abundant, diverse marine life • ‘Marine Conservation Zone’ • Manta, Turtles, Dolphins, Sharks, Jacks, Morays • Adventurous & challenging – self-help, teamwork, leadership, initiative, planning, organisation, camaraderie, compressor operation, boat and dive management • Sub-tropical, clear water, dependable conditions • British Overseas Territory • CNFP MOD flights – easier overseas expedition & financial approval process • Good value, cost effective
Typical Diving Conditions • Sunny, partially cloudy • Water temp: 23-28C • Air temp: 21-27C • Prevailing winds 130 • Tidal range <1m • Current - no / slight westerly flow • In-water visibility – excellent • Boat traffic – very little • Netting / lines – little to none • Caution – Large surface swells • Forecast safe diving limit ≤ 2.5m
Dive Profiles • 12 ltr cylinder • Open circuit • Nitrox / Air • Dive computer • 30m maximum depth • Conservative profiles - no planned mandatory decompression stops • Descent / ascent line • 3-minute safety stop
Typical Exped Modus Operandi • 12 expeds per year • No diving expeds Dec–Feb incl • 12 divers / exped • 12 days on island • Arrive ASI - Mon early am • Depart ASI - 2nd Fri night • Cease diving – 2nd Thurs pm • 2 day dives: • Morning dive • Charge cylinders / refuel / lunch • Afternoon dive • Optional night dive • ~18-20 total dives per person
Equipment • Non-publicly funded • Acquired, maintained, serviced, tested by RAFS-AA ‘working parties’ • General Engineering Flight • Gas purity checks • Annual inspection DSO(AT) • Fully compliant
Equipment • 2 RIBs / 55 HP engines • Ferry RIB • Nitrox membrane compressor • Electric air compressors x 2 • Cylinders • Weights • Shot lines / buoys • Mooring buoys • Boat anchors • Fuel cans / bags Exped Responsibility • Personal dive kit
Safety Equipment • Nitrox membrane compressor • Emergency Position Indicating Radio Beacons & waterproof canisters • O2 cylinders • RescuEAN pods x 2 Exped Responsibility
Risk Mitigation & Control Measures • Fit military population • BR1750A periodic medical examination & annual review • DVD boat loading procedures • Dive planning and organization • Pre-exped risk assessment • Dive planning – identify specific hazards, risks and control measures for dive • Comprehensive dive brief - weather & sea conditions from ASI Met Office • Book in / out by telcon - Ascension Ops • SEEDS brief • Pre-dive BAR(E) safety check • SADS dive manager – dynamic risk assessment • JSSADR • BSAC Safe Diving • Debriefs
Emergency Assistance PlanRescue / Emergency Services Medical Centre • EAP • RAFS-AA website • On-island procedures rehearsed & tested annually • No recompression chamber • Ascension Island Fire & Rescue Lifeboat • 24-hr cover, 30-33 kts • GPS, Radar, VHF, EPIRB • 2 x 60-man life rafts • No SAR helicopter • Ascension Radio / Base Ops • VHF 16 / Sat Phone • Mil Med Centre • Georgetown Hospital Georgetown Hospital
DCI Risk – Control Measures • Medicals • Nitrox • 30m maximum depth • Conservative profiles - no mandatory decompression stops • 24-hr break after 4 days diving • 3-minute safety stop • Nitrox – use air no-stop decompression limits • Descent / ascent line • JSSADR • BSAC Safe Diving • O2 kit • RescuEAN pods
DCI Incident Rate • 1982 - first exped • 1984 - regular expeds ~ 12 expeds of 12 divers / year ~ 2,800 dives / year 28 years of expeds Total Dives ~ 88,000 DCI Incidents – 0
Probability of DCI Incident Next Dive 3 Total No of dives occurred so far without mishap = 3.4 x 10-5 Very small DCI risk
Risk in Perspective • 1 in 1000 as the ‘just about tolerable risk’ for any substantial category of workers for any large part of a working life • • 1 in 10,000 as the ‘maximum tolerable risk’ for members of the public from any single non-nuclear plant • • 1 in 100,000 as the ‘maximum tolerable risk’ for members of the public from any new nuclear power station • • 1 in 1,000,000 as the level of ‘acceptable risk’ at which no further improvements in safety need to be made
DCI Risk MitigationNew Control Measures • Mandatory 24-hr breaks after 4 days diving Recommended that no more than 3 dives be performed in any 24 hrs. Any dive series involving consecutive days diving to 30m+ should be limited to 4 days, after which a 24-hr break should be taken • Mandatory 3-minute safety stop • Nitrox – mandatory use of air no-stop decompression profiles Maximum depth in ASI ≤30m More cautious, greater margin of safety
Flight Schedule 2012 • Ascension to Brize Norton • 2 flights per week • Tues & Fri – evening • Ascension to Falklands • 2 flights per week • Mon & Thurs – morning • USAF flights 4+ flights / week for potential CASEVAC tasking
AT Medical / CASEVAC ‘MOD will facilitate medical treatment for personnel whilst on AT, including, if necessary, medical evacuation. This may include rescue/recovery from the accident site when necessary’ ‘MOD will bear the cost of medical/rescue treatment and worldwide aero-medical evacuation for Service personnel on authorised AT 2009DIN01-050
SummaryDiving Defensively, diving conservatively • Unique location, opportunity, facilities • Adventurous - controlled exposure to risk • Comprehensive risk mitigation and controls • Proven, excellent safety record • No DCI incidents
SummaryDiving cautiously, diving conservatively ‘The value of AT lies in the recognition and effective management of risk through a systematic approach to recognizing risk and taking preventative or controlling action’