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

• 480 nm south of Equator• ~ 9 hr flight from UK• 810 nm SSW Liberia• 1200 nm Brazil (Recife)

• 480 nm south of Equator• ~ 9 hr flight from UK• 810 nm SSW Liberia• 1200 nm Brazil (Recife)

Ascension Island

Dakar

Canary Islands

Brazil

Location

ExpeditionCentre

English Bay& Jetty

Georgetown•Lifeboat•Hospital

Travellers Hill•Accommodation

•Messing

Airfield•Ops & Met Office•Medical Centre

Orientation

Expedition Centre

• Ablutions• Dormitories• Kitchen• Crewroom/classroom• Equipment store• Compressor area• BBQ / patio area

Dive Site Locations

North

Prevailing wind direction – 130o

Boatswain Bird Island / Rock

Dive Sites

• 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

Wall

Comfortless CoveSWTA

English Bay

Confined Water / ApprovedSwimming Areas

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

Value of Diving Ascension

• 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

Typical Diving Conditions

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 • Sat Phone • Knife / Line Cutter • Depth sounder

• O2 masks / kits

• Delayed SMBs • Hand-Held VHF radios

• First aid kits • Other signalling aids

Hazards & Risk - Risk AssessmentHazard Risk Frequenc

ySeverity Risk

EvaluationControls Immediate Measures

DCI (DCS and / or Barotraumas)

Serious injury/death of diver

Rare High High Thorough and accurate dive planning. Divers should agree a dive plan with the SADS/Dive Manager before the dive. Dive the plan. All divers to use computer or BSAC 88 tables to plan/execute dive profile. Divers should avoid aggressive dive profiles and ensure they have sufficient gas for the planned dive, including 3-minute safety stop. Divers should ensure they are properly weighted and capable of making a safe and controlled ascent, and that inflation and dump systems are working correctly. Divers to remain well hydrated and avoid excessive exercise after diving. If diving on computers, divers to have a contingency plan for computer failure e.g. watch and dive tables SADS to ensure oxygen kit checked and fully functional and O2 administrator on boat. De-kit before getting out of water. Minimize physical activity/exertion after dives.

Oxygen kit and trained O2 administrators on site. Dive Manager (or designated diver) to contact Ascension Radio/Ops ASAP. Use Emergency Assistance Plan. Land casualty at Guano Jetty or Georgetown. Incident Procedure/DCI assessment sheet to be completed and accompany diver to emergency services. Incident to be referred to DDMO ASAP. Casualty to be referred to recompression facility.

Large surface swells Damage to boat and diving equipment. Serious injury to divers

Occasional High Medium No diving operations if forecast swell > 2.5m. Post look-outs during ferry boat loading and unloading.

Back off ferry boat immediately on notification of a swell by the lookout. Personnel and equipment stay/placed on high ground.

Deteriorating weather Risk to boat andpassengers

Occasional Low Low Usually a good weather factor. Dive Manager to plan dive using updated weather forecast, and to have contingency dive site. Continuously monitor conditions prior to and during dive and abort dive if necessary. Book in/out each dive activity with Ascension.

Dive Manager to cancel diving or change to back-up site. Recall divers if dive in progress

Disorientation / entrapment during swim throughs

Panic, entrapment, injury to diver, running out of air, serious injury to diver, death

Rare Medium Medium Divers to avoid entering swim throughs unless they have clear entry and exit, or are suitably trained and equipped. Divers to carry/use guidance line /rope. Gas to be checked immediately prior to penetration. Careful fining technique to minimize silt disturbance.

Assistance from buddy

Diver falling when exiting water or generally during entry/exit

Serious injury to diver

Occasional Medium Medium Divers to ensure they are never beneath a diver climbing up a ladder or entering/exiting water.

Recover casualty from water and administer first aid. Hospitalise, asrequired.

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

• 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

Medical Centre

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 expedsTotal 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 divingRecommended 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’

Questions