Published December 15, 2016 | Diving, Duiken

A DSMB (Delayed Surface Marker Buoy) is used by the diver to communicate with the boat of surface crew while the diver remains under the water. It is used for various reasons including:

  • To mark a location
  • To indicate distress
  • Need for more air

A DSMB (Delayed Surface Marker Buoy) is a tubular buoy that is made from PVC or other materials that may be similar. They are attached to a spool or a line reel. They come in bright colors including yellow, red and orange and in some cases the colors may be used to pass on a different message.

surface marker buoy

Effective Deployment

It is important for you to learn how to properly deploy your delayed surface marker buoy when diving. Here is a guide that you can follow:

  1. When you make a safety stop, DSMBs will often be launched. As such, you need to know how to deploy it mid-water. In order to do so, your buoyancy skills will need to be good. When the time comes to launch, first find your best hover point, then let out a little air so that you are a little bit negative in the H₂O.
  2. Not remove the DSMB, unpack it and take care so that you don’t drop its reel. Since it does not come with a lock, should you drop it will unravel to its entire length before it can stop, coiling it up will be a mess.
  3. Grasp the line spool and the DSMB with the left hand so that the right one is free to open up the DSMB at the bottom.
  4. Now turn your head to a slight tilt so that on or off, the regulator exhaust valve is near the DSMBs opening. You should take care so that you do not have the line getting wrapped up in the regulator or its hose.
  5. Breathe in moderately and then bring the DSMBs opening and position it above the valve, then exhale. The gas you exhale will then move from your exhaust valve to the DSMB.
  6. You may need to repeat this one or two times until the DSMB gives a strong tug. (You will need to counter the DSMBs positive buoyancy using your breathing. Alternatively, you can let out a little air from the BSC.) Now release the DSMB while holding the spool with your left and right index fingers. Give it room to unreel as needed.

Once you get it right, you are good to go and practice makes perfect. Visit our website and contact us so that we can arrange your next diving trip.