Frequently Asked Questions

View Product Instruction Manual

1 - What is the SOS Dan Buoy 33 inflatable marker man overboard system?

  • The SOS Dan buoy 33 is the first inflatable marker Dan Buoy to have the testing to International Standards ISO 12402
  • SOS Dan Buoy has the capability to fulfil a need for all boats; from navy boats to yachts and power boats both small and large in the areas of professional safety and rescue.
  • Developed by SOS Marine, Australia.
  • The SOS Inflatable Marker Dan Buoy provides rapid flotation assistance to a person at risk of drowning.
  • Unique design features include the ability to have this compact valise ready for use. Just throw in the water.
  • Superb functionality, portable, simple and easy to operate by all ages, and not restricted by geographic areas or language problems.
  • Once thrown into the water the SOS Dan Buoy is inflated standing 2.5 metres above the water, (using a similar mechanism to an inflatable life jacket).
  • It is weighted down to stand vertically in water, has a sea anchor to drift with the current-similar to a person in the water
  • Highly visible up to 1,700 metres (1 mile) away
  • Two webbing loops are located just above the surface of the water to enable the person to hold onto awaiting rescue.


Attention to detail has been given to all aspects of this high quality SOS Dan Buoy 33 inflatable marker. It is easily stowed, low maintenance and reusable making the product environmentally sustainable.
This improvement in safety has positive advantages for the marine market in every country that has boats on water both inland and sea.
It has been trialled and tested by navy defence and police air wing.

"It holds up exceptionally well in terms of originality, visibility , durability, maintenance and serviceability and can be used for highly diverse rescue operations".


2 - How does the SOS Dan Buoy work when someone falls overboard?

The compact SOS Dan Buoy33 is ready-to-go, just throw and inflates when it hits the water.

  • It is housed in its own valise.
  • When there is an emergency of MOB this simple safety aid can be thrown as is, no need to set or activate.
  • It is water activated within seconds of immersion and stands 2 metres above the water level.
  • The SOS Dan Buoy then inflates marking the area where the swimmer is.
  • The SOS Dan Buoy has a large sea anchor, grab handles, whistle and ribbon flying from the top.
  • The combination of the fluro yellow colour, SOLAS reflective patches and the ribbon makes spotting much easier.
  • It has SOLAS reflective patches and grab handles for the swimmer to use to assist in supporting them.
  • SOS Dan Buoy uses have expanded as each purchaser introduces it into boating experiences

Such as:

  • temporary channel marker
  • boat handling training aid
  • dive site


3 - What are the design features of the SOS Dan Buoy MOB system?

Design Features

  • Ready-to go, no assembling, “light and easy “ to use
  • Only Dan Buoy world-wide tested to elements of ISO 12402
  • Grab handles for security of person overboard
  • High visibility marker allowing it to be seen 1700 metres (1 mile) has 2.5 metre (8.2ft) streaming ribbon
  • SOLAS (automatic) light for night rescues
  • Weights only 4 kilos (8 ½ lbs) can be used by everyone on board in an instant (similar size to ladies handbag)
  • Service Window detecting at a glance set- to-go
  • Reusable and can be repacked, requiring a 33 gram cylinder and UML cartridge
  • Large drogue (120cm x 60 cm long) (3½ ft x 1½ ft) designed along life raft specifications
  • The drogue can be removed and attach an anchor for temporary marker for wrecks, channels dive or crash sites.
  • Compact, portable and smaller than a tackle box easily transported from boat to boat
  • Can be used in fresh and salt water
  • Rescue helicopter pilots find the SOS Dan Buoy an effective and accurate rescue system to indicate wind & current directions at water level.
  • In difficult and dangerous rescue operations deployment of several SOS Dan Buoys can be dropped from helicopter to assist in operational timeline.


4 - How do I service and maintain the SOS Dan Buoy system?

Your SOS Dan Buoy is an important piece of safety equipment and needs to be properly maintained and serviced throughout its lifetime.

This is to confirm that the first service of the Dan Buoy is 12 months after date of purchase and subsequent services should be within 12 months following previous service.

Service procedures of the SOS Dan Buoy33 are explained in Manual of Instruction included in the original purchase or click here

The service should be carried out by properly trained personnel.


Please view UML service website to find out more about your replacement cartridges

World -wide Service Centres

Manual of Instruction

5 - Where has the SOS Dan Buoy 33 been tested?

SOS Dan Buoy 33 was tested to elements of the ISO 12402, first of its kind

Testing is carried out at the Fleetwood Testing Laboratory + UKAS Testing
in Lancashire who are accredited by The United Kingdom Accreditation Service (UKAS)

6 - What spare parts are used in the SOS Dan Buoy 33?

  • 33gram cylinder CO2 inflation system
  • UML Auto Inflator and automatic inflation cartridge

Automatic-Latest Pro-Sensor Inflation technology. The Pro-Sensor is fitted with the latest all weather cartridge with the added benefit of inhibiting the accidental ingress of moisture and water spray during hot humid or heavy stormy weather should not activate the inflation system. The lightweight water-activated inflation system requiring a self-contained disposable CO2 inflation system (the same mechanism as an inflatable lifejacket). The cartridge also has an expiry date and it has to be replaced prior to expiry.

Please view

Service Window provides at a glance that the SOS Dan Buoy 33 is set to go

  • Water activated SOLAS Flashing light

It is activated automatically to output white flashing light when the water sensors contact with water. Under flashing working status, After activated, it is available with the operating sequence “FLASHING-STEADY-SOS-OFF” by the manual switch.

The light can be seen clearly from at least 1.5km in 360° directions so that it can increase the success chance of rescue. The exposed materials are anti-UV and corrosion resistant. The structure is so compact that the light is completely waterproof under 1m depth of water. The clip makes installation easily and firmly.


7 - How does the SOS Dan Buoy 33 automatic inflation system work?

Please also refer to UML website

It is important that all users are aware of the type of inflation system fitted and how it activates.

For automatic operation, a full CO2 cylinder and a serviceable cartridge mechanism must also be fitted and not blocked from water entering the system.

We recommended checking the inflator before donning the SOS Dan Buoy (see service window on dan buoy) ensuring the CO2 is not pierced and fully screwed in tightly by hand and that the cartridge mechanism has not expired and is fully screwed on tightly by hand.

Ensure the inflator is in good condition and not damaged and all indicators are present and correct. The UML Automatic system activates when the cartridge mechanism comes into contact with water. The cartridge mechanism is a compressed high-powered spring which is held by a paper element. When the paper element comes into contact with water it releases the spring which pushes a plunger forward, in turn forcing a cutter into the CO2 cylinder. The cutter allows the CO2 to travel through the CO2 gas hole in the inflator head and inflate the lifejacket.


The Pro Sensor® Automatic incorporates the added advantages of an indication system, that:

  • Indicates the CO2 Cylinder is pierced.
  • Indicates the CO2 Cylinder is correctly fitted.
  • Indicates the status of the automatic cartridge.
  • Indicates the automatic cartridge is correctly fitted.
  • Replacement UML automatic inflation cartridge only (without CO2 cylinder). This inflation cartridge triggers inflation of dan buoys with UML Pro Sensor inflation mechanisms. Replacement of this cartridge in your SOS Marine dan buoy is recommended every third year, but in heavy tropical climate, annual replacement is suggested.
  • Please check the cartridge also has an expiry date and it has to be replaced prior to expiry.


8 - How do I care for my SOS Dan Buoy 33?

Please take care of your SOS Dan Buoy 33 it is an important piece of safety equipment and needs to be properly maintained throughout its lifetime.
The SOS Dan Buoy`s are sold around the world, they all have UML auto inflation system. Please also refer to UML website for information about auto inflation system.

"Your SOS Dan Buoy is valuable it is recommended to store this product inside cabin when your boat is unattended- Also, stow your SOS Dan Buoy in cabin when weather and waves are repeatedly excessive."

Use the Rail Mount Holder to stow your SOS Dan Buoy externally and when not in use store inside cabin.

At SOS Marine we take great care in the design so that many parts can be repaired or replaced if damaged. In most cases this avoids the cost of complete replacement.

Please Note: “Water must run up inside the bobbin to active the inflator, water washing down and over the inflator will not active your SOS Dan Buoy 33.”

9 - What is a Rail Mount Holder?

The SOS Dan Buoy rail mount holder is an easy to use container made to be mounted on the rail to contain your SOS Dan Buoy 33

In the event of a man overboard-simply flip open the SOS Dan Buoy holder

  • Remove the SOS Dan Buoy and throw
  • The SOS Dan buoy 33 automatically inflates once in water.


10 - How do we repack our SOS Dan Buoy 33 correctly?

The SOS Dan Buoy33 can be used in fresh or salt water and when recovered after use it can be recharged and repacked for future use.

It is important that it is repacked correctly.

Only requires a 33 gram replacement cylinder and UML activation cartridge

Instruction Manual or view THE PREPACKING VIDEO


11 - Does the SOS Dan Buoy 33 meet the Off Shore Sailing Safety Regulations?
12 - What is the difference between SOS Dan Buoy 33 and other products?

1. Tested to elements of the life jacket standard ISO 12402

As far as we know, it is the only dan buoy tested to elements of the International Life jacket standard ISO 12402

2. The oversized drogue

We have heard criticisms that drogues on man overboard devices were not large enough, from survivors who lived to tell us. They were frustrated at having to swim after devices being blown away from them in severe weather. The self–inflating SOS Marine dan buoy uses an extra large drogue (47″ by 23 ½″ / 600mm x 1200mm) as a result of this input.

3. Webbing grab handles

By having webbing grab loops as opposed to handles allows the swimmer to reach the SOS Dan Buoy and place their arms around the inflated marker for support and flotation, giving an extra sense of security when fatigued.

(NOTE: Holding handles create cramps in the hands. The SOS Dan Buoy has the ability to put your arms through the loops to provide a more comfortable and stable solution).

4. Service Window

Inspection/Service Window provides at a glance that the SOS Dan Buoy 33 is set to go.

5. SOLAS Reflective Tape

The SOS Dan Buoy has 6 of 100mm x 50mm on the inflatable section and two (2) 100mm x 50mm on the ribbon. All SOLAS approved.

6. High visibility

Confirmed visuals at sea level up to 1700 metres in 2 metre seas, wind strength 20 knots.

7. Whistle- SOLAS Approved

8. Automatic-Latest UML Pro-Sensor inflation technology

The UML Pro-Sensor is fitted with the latest all weather cartridge with the added benefit of inhibiting the accidental ingress of moisture and water spray during hot humid or heavy stormy weather should not activate the inflation

9. SOLAS flashing light

10. Re-usable

After replacing the 33gram gas cylinder and UML operating head and correct repacking.

SOS Dan Buoy 33 Compared to old style stick dan buoy;

  • STICK dan buoy- two part unit requires to be put together or stored assembled which creates storage and handling problems.
  • STICK dan buoy-requires assembling or if stowed assembled it is cumbersome to handle. The flag has to be unfurled before launching
  • STICK dan buoy has NO light
  • STICK dan buoy has flag with NON SOLAS tape on one side cannot be seen directly up wind or downwind.
  • STICK dan buoy is on 15 mm thick and cannot be seen from a distance
  • STICK dan buoy has NO drogue-drifts with the wind
  • STICK dan buoy has NO inflation system-requires assembling an unwrapping of flag.
  • STICK dan buoy has limited visibility
  • STICK dan buoy has NO whistle
  • STICK dan buoy has 1 piece of NON SOLAS reflective
  • STICK dan buoy has NO support for MOB
  • STICK dan buoy has NO attaching point for life buoy


13 - Can I carry my SOS Dan Buoy on aircraft?

If you are intending to take your safety equipment SOS Dan Buoy 33 with you on board an airplane you may wish to read the following advice to ensure a hassle free journey.

You may not be aware, but travelling with inflatable rescue products on board aircrafts can be difficult due to the fitted CO2 gas cylinders. These are classed under the International Air Transport Association (IATA) Dangerous Goods Regulations and require you to get approval from the operator before taking them on board. This means that you MUST contact your operator in advance of your flight or booking and clarify with them their position on the carriage of SOS Dan Buoy 33 fitted with CO2 gas cylinders.

Please view and open here for details to carry SOS Dan Buoy on board and airplane in United States +

14 - Can the SOS Dan Buoy be dropped from a helicopter?

Yes, the SOS Dan Buoy 33 has been dropped from 200ft at 60 knots from a helicopter.

Several SOS Dan buoy`s have been successfully dropped from a fixed wing aircraft from 1000 feet.

15 -Can I Mount SOS Dan Buoy upside down?

No !


Do not mount dan buoy upside down

  • The dan buoy is not engineered to be mounted upside down.
  • It should be mounted so that the deployment handle is up. Another way to say this is that the dan buoy needs to be mounted right side up.
  • With handle up, it is easier to grab to readily throw the dan buoy, while also permitting water to easily drain through grommets in the bottom of the dan buoy outer sheath.
  • Mounting the dan buoy upside down can permit water to collect in the self-inflation mechanism, which can cause the dissolving pill to dissolve before you need it to. Mount the dan buoy right side up, with the handle upward.

16 - Does SOS Dan Buoy 33 satisfy ISAF sailing MOB pole requirements?
17 - How to Find and Rescue Man Overboard?
18 - Does Dan Buoy Satisfy US Sailing™ Equipment Requirements?

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