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
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Dive Sites
Value of Diving Ascension
Typical Expedition and Diving Conduct
Equipment
Hazards, Risks and Control Measures
DCI Risk
Location
Canary Islands
Dakar
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480 nm south of Equator
~ 9 hr flight from UK
810 nm SSW Liberia
1200 nm Brazil (Recife)
Ascension Island
Brazil
Orientation
English Bay
& Jetty
Georgetown
• Lifeboat
• Hospital
Expedition
Centre
Travellers Hill
•Accommodation
•Messing
Airfield
•Ops & Met Office
•Medical Centre
Expedition Centre
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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
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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 / Approved
Swimming 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
Value of Diving Ascension
Typical Diving Conditions
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Sunny, partially cloudy
Water temp: 23-28C
Air temp: 21-27C
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
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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
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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 Assessment
Hazard
Risk
Frequency Severity
Risk
Evaluation
DCI (DCS and / or
Barotraumas)
Serious
injury/death of
diver
Rare
High
Large surface swells
Damage to boat
and diving
equipment.
Serious injury to
divers
Risk to boat and
passengers
Occasional
Panic,
entrapment, injury
to diver, running
out of air, serious
injury to diver,
death
Serious injury to
diver
Deteriorating weather
Disorientation /
entrapment during swim
throughs
Diver falling when exiting
water or generally during
entry/exit
Controls
Immediate Measures
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.
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.
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
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
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, as
required.
Risk Mitigation & Control Measures
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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 Plan
Rescue / Emergency Services
• EAP
Medical Centre
– RAFS-AA website
– On-island procedures
rehearsed & tested annually
– No recompression chamber
• Ascension Island Fire &
Rescue Lifeboat
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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
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Mil Med Centre
Georgetown Hospital
Georgetown Hospital
DCI Risk – Control Measures
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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 nostop 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 Mitigation
New 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
Maximum depth in ASI ≤30m
More cautious, greater margin of safety
• Mandatory 3-minute safety stop
• Nitrox – mandatory use of air no-stop
decompression profiles
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
Summary
Diving Defensively, diving conservatively
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Unique location, opportunity, facilities
Adventurous - controlled exposure to risk
Comprehensive risk mitigation and controls
Proven, excellent safety record
No DCI incidents
Summary
Diving 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