Diver Location Aids: HSE Report


Some of the raw data is not presented here to save on space: all the results have been documented in the preceding text.

Table 1: Abbreviations used when presenting data.
Abbreviation Device
YF Yellow flag
RF Red flag
OF Orange flag
AF A flag
BF Black flag
PYB Pink and Yellow buoys
1RB One red buoy
2RB Two red buoys
AP DB AP Valves red decompression bag (self-inflating)
AP DS AP Valves red decompression sausage (self-sealing)
BR DS Bowstone red decompression sausage
BY DS Bowstone yellow decompression sausage
YSMB Yellow self-deploying SMB.
DH Divers head
JS Jotrun strobe
SS Seaman Sub strobe
UK1200 Large lantern torch
UK400 Medium lantern torch
SL4 Medium torch
MiniQ Small torch
OS Orange Smoke
NF Night flare
MF Miniflare
MD Marker dye

Table 21: Device specifications

Device Specifications Cost
Sea-Streak marker dye Tablet of dye in peel open dispenser, green/yellow dye 15
Sea marker dye Powdered dye in peel open dispenser, green/yellow dye Manufactured by Presto Dyechem 14
Folding flag Total height 1.8m Height above sea level when held by diver 1.3m Pennant size: 50cm x 50cm 15
Jotrun strobe No specifications available 70
Seeman Sub Signal Flash Flash performance: continuous flashing for 15 hours Waterproof to 50m Visibility: over 3km on clear night with unobstructed view 22
Pains-Wessex Day & Night Signal Ends of flare are fully waterproofed with 'o' ring seals. Ideal for divers. Burning times: Red flare 20 seconds of 10,000 candela Orange smoke: 18 seconds minimum 32
Pains-Wessex Miniflare 3 8 red aerial flares projected to a height of over 80m with a flare burning for 6 seconds at 3,000 candela 27
Bowstone decompression sausage Height: 1.35 m Width: 9 cm 15 AP Valves SMBC decompression sausage Height: 1.40 m Width: 10 cm 30
AP self-inflating decompression bag Height: 75 cm Width: 55cm 120
Polyform buoys Diameter: 40-50 cm 5
MiniQ torch 2.1 Watts power output Burn Time: 5-6 hours 15 SL4 torch 5.5 Watts power output Burn Time: 4-5 hours 25
UK400R torch 18 Watts power output Burn Time: 1 hour 100
UK1200 torch No specifications 150




Q1. What location devices do you use?

Self deploying SMB (ie a surface buoy that pays out a line as you descend)
Delayed surface marker buoy (open ended bag/sausage, self inflating bag, other; what colour is it?)
Folding flag (What colour is the pennant eg red, orange, A flag, day glow yellow?)
Torches: (small backup / lantern or other)
Strobes: (Jotrun, Seeman Sub or other). Where do you attach your strobe?
Pyrotechnics: (Miniflares, day/night distress signal)
Sea marker dye:
Bright hood/reflective strips:
Light sticks:

Q2. Do you have any experiences of relocating missing divers?

Q3. How long were they on-surface before recovery?

Q4. Did the diver/s use any location device?

Q5. Have you ever been missing / temporarily lost by your support vessel?

Q6. If so, how long did you wait for recovery?

Q7. Did a location device promote your recovery?

Q8. What was this device?

Q9. Are you colour blind?

Q10. Have you ever found any particular colour/s stand out better than others?

Q11. Do you have any other comments regarding diver location devices?


Table 22 Recreational diver questionnaire responses

No. sdSMB deSMB col Flag col Torch Type Strobes Attach Pyros Whistles Dye Hood
Lsticks Other
1   y R     y s y L   y     oc  
2 y y Y y DGG y L y st       y deep  
3 oc y   y O               y nd  
4   y Y y Y y s               Fins
5   y O     y s     y y   y nd  
6 y y       y s y     y   y nd  
7   y O     y L       y   y nd  
8 y y Y y Y y m.L y st   y   y    
9 y y O     y L y st   y   y nd reflectors on stab
10 oc y O     y s,m,L       y        
11 y                            
12   y O y DGY y bk,L y st y y     nd  
13 y y R     y L       y       mouth
14 y y R     y s,L y st   y        
15 y y O     y s y st   y        
16 y y O     y s,m,L y              
17 y y R y DGY y bk,L       y   y   mirror
18 y y O y R y s,L       y        
19   y DGO y R y L,L       y     nd yellow stab
20 y y       y s,L       y   y nd  
21   y   y DGO y s,m,L y h         nd  
22   y O y   y 2 s,L y p   y        
23   y O y O y m,L                
24 y y O y O y 2 s,m,L n     y     nd  
25   y O     y bk,L y st y y        
26 y y O               y        
27 y y O     y bk y st   y       DGO drysuit
28 y y       y s,L y st   y     nd  
29 y y DGO     y bk,L y st   y   y nd  
30 Y Y 0 Y Y Y bk,s,L       y       DGY Fins
31 oc y O     y s,L       y   y    
32 y y O     y s       y   s    
33 oc y       y L               air horn
34 y y O y R y L       y   y    
35   n   y R y mbk,L                
36 y n       y         y        
37 y y O y R y sbk,L y st   y     nd  
38 y y O     y s,L y st   y   y nd  
39   y O     y s                
40   y DGO     y L       y        
41   y O     y L       y        
42   y R y Y & R y sbk,L       y        
43 oc y O     y mbk,L y st y y        
44 oc y O y Y y L y st   y        
45 y y   y   y   oc       y   oc  
46   y O     y sbk,L y st   y     nd  
47 y y O y DGP y sbk,L       y     nd  
48 y y O     y sbk,L y st   y     oc  
49 y y O y O y bk,L y st   y     y  
50   y R y O     y st   y        
51 y y DGR     y sbk,L       y   y y  
52 y y   y R y   y st       y    
53 y y O y O y             y    
54 y y   y DGY y s                
55 y y DGY y O y sbk,L y st nd y   y nd  


a = always oc = occasional nd = night dive deep = deep dive h = head L = lower arm st = stab-jacket col = colour

s = small m = medium bk = backup L = Lantern sdSMB = self deploying surface marker buoy delSMB = delayed surface marker buoy Lsticks = light sticks

DG = day-glow P = Pink Y = Yellow G = Green O = Orange R = Red B = Blue Bl = Black W = White


Table 22 Questions 2 to 10

No. Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10
1       n       n R,O,Y
2 y 60 Flag y 50 y Torch n DGO, DGY, DGG
3 y 30 deSMB y   y Flag n None
4 y 10 SMB y 60 n   n O
5 y   y n       n  
6 y 5 deSMB n       n Colour depends on conditions
7 y 45 deSMB,Flag y 15 n   n  
8       n       n Depends on conditions
9 y 20 deSMB y 45 y deSMB n O
10       n       n O, bright green
11 y 5-10 arm y 10 y speargun n O, R, Y best B, G , Bl & W worst
12 y 10-20 Flag y 10 y flag n O, Y
13       y 2 y whistle y Prefer DGY to R or O
14 y 30 flare, deSMB y 5-10 y deSMB n R & DGO is better than DGY
15 y 5 deSMB n       n O, R & silver
16       y 15-20 y deSMB n O, Y better on dull day
17 y 20 deSMB n       n DGR,DGO
18 y 10 deSMB n       n O or Y
19       n       n DGY or O
20       y 10 y Flag n O
21       n       n Y or bright O are more visible than A flag
22 y 15-20 Flag n       y Black seems to stand out well
23       y 5-10 y Flag n O
24 y 90 n n       n O better than others
25       y 10-15 y SMB n O
26 y 120   n       n DGO
27       N       n O
28       y 60 y O sausage & reflective hoods n All fluorescent colours
29     DeSMB y 5 y Flag n Y on dull day. O easier on bright day
30       y 10 y deSMB held as flag n DGY best
No. Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10
31       n       n  
32       n       Partly  
33       y 10 y Flag n R/O better than Y/G, especially sunny days
34       n       n  
35       n       n DGO
36 y 3 n y 5 y Whistle n DGO
37 y 30 Whistle,delSMB y 45 y Whistle,delSMB n O
38       y 5 n     DGG
39 y 2 deSMB y 10 y Whistle, torch n DGG & DGP
40 y     n       n  
41       n       n Bright days - O/R, Dull days - Y
42       n       n Bright conditions - O better than Y. DGP best
43 y 180 n y 20 y Flag n  
44 y 30 SMB y 20 y   n DGR
45       y 15 n deSMB,whistle n Lime Green
46       n       n DGP/DGO better than DGG/DGY in bright conditions
47 y 10 Buoys & Strobes n       n Y & O
48       n       n  
49       n       n R
50       n       n DGR & DGO
51       n       n n
52       n       n Red / Yellow
53       n       n DGO & DGY
54       n       n n
55       n       n R,O & Y



Q11. Do you have any other comments regarding diver location devices?

Flag best (simple, reliable) even catch light glimpse at night. Not convinced that it is possible to work flares with cold wet hands, difficult to blow whistle if full of water, and cold lips. Visual aid better, best if whistle in conjunction with this.

Flags very useful, especially rough seas, but not cheap.

Flag is very effective in daylight. It gives a much greater height than other manual devices and is convenient to carry strapped to the tank. Until you see it you don't realise how effective it is.

Flag best - cost effective, stowed easily by tank, easily deployed, and very visible with sufficient extension.

Flags are one of the best in my opinion.

All should be encouraged to carry a flag on open water dives. They are simple, cheap and require no maintenance or batteries.

I am considering an orange or day-glow flag.

Visual device is better than audible. Plan to get a flag.

Bright coloured SMB or Flag advantage to hold above waves, and not too expensive.

What do fisherman always use - BLACK! Orange is much easier to see than lime green. Would like EPIRB, but expensive.

Would consider EPIRB. Taller SMB stands out more, filters to identify strobes.

Colours must be bright but not too light / pale. Pyrotechnics used in remote location but only survive 25 immersions and are quite pricey.

DGY not very effective in bright sunlight, flares go out of date.

Fluorescent colours when overcast, R/O on sunny days. Used to carry a DGY flag but found it too bulky and offered little benefit over delayed SMB.

Red/Green colour blindness but never had any problems distinguishing colours of SMB's. Whistles next to useless (invariably wind blows sound wrong way). Sausage shaped SMB's tend to fall over.

Would like EPIRB, but expensive. Yellow items disappear in strong sunlight. Shape important. Movement attracts eye. Flares preferred, than sea dye for air search.

Inflated sausage SMB can be waved at boat; the more affordable, most frequently used. Most easily stowed, reliable.

Flares seem good idea, but uneasy about potential hazard of igniting accidentally.

Pyrotechnics only presumed functional until required. SMB's don't show on boat radar. Only SMB works underwater.

4ft high SMB easily lost by vessel in swell. Small SMB's no use in rough seas. Can only spot sausage-shaped SMB's. Open-ended tend to fill with water and sit lower in the water.

What about air horns? Tomorrow's world are always ecstatic about white noise!

Always picked up delayed SMB before diver reaches surface. Non-attentive skipper - few devices help!

Need several types, no one good for every situation.

Divers between sun and boat, no device for this.

Device is specific to situation. Best visual aid in daylight - flag/SMB; night-time - torch/SMB/Light stick. Plus competent skipper / shore cover.

Prevention is better than cure.

Experienced skipper very important.

Must carry a location device on 100% of dives.

More allows redundancy and choice.

Many small boat operators do not know how to search for a diver.

Little diver training for diver location devices.

Dive alert' air powered whistle, very effective at close range (<500 m), plus deco-bag & self-sealing sausage good combination. Smoke more effective than flares. To develop something which is small, unobtrusive, and cannot be set off by accident! Dislike buzzers - impossible to locate and can be confusing and stressful to divers, especially trainees.



We wish to acknowledge the assistance of, and resources provided by:

Health & Safety Executive. MCA MRSC Pentland. MCA MRSC Shetland.
Oscar Charlie, SAR helicopter, Bristow Helicopters Ltd, Shetland.
RNLI Stromness lifeboat. RNLI Longhope lifeboat.
Jean Elaine and skipper, Mr Andy Cuthbertson. Girl Mina and skipper, Mr Terry Todd. Ramsay Dyce and skipper, Mr Keith Oliver.
Department of Harbours, Orkney Islands Council.
Lerwick Harbour Trust, Shetland.



Alister Wallbank Colin Bullen Carol Daniels Bill Chilton Dr Jon Side

ICIT, Department of Civil & Offshore Engineering Heriot-Watt University Old Academy Back Road Stromness Orkney.



Light Measurement Handbook: What is light? Alex Ryer, International Light, Inc. 26th September 1997

Diver Magazine, 'The view from the chopper', July 1997, Eaton Publications.
Also available at http://divernet.com/safety/helic797.htm

3 Personal Communications. Orkney shellfish divers. Mr A.Elder, Mr J.Simm, Mr P.Tulloch, Mr M.Sinclair

Commercial Shellfish Diving in Inshore Water - Diving at Work Regulations 1997, HSE

Sports Diving Incident Reports 1996/97 and 1998 compiled by Reg Hill, National Diving Liaison Officer, MCA, Brixham.

Light Measurement Handbook Diver Magazine Pers. comms.

Orkney shellfish divers Commercial Shellfish Diving in Inshore Water - Diving at Work Regulations 1997

Sports Diving Incident Reports 1996/97 and 1998




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