How to deploy a DSMB – delayed surface marker buoy

One of the most important skills a diver can have is how to correctly and safely deploy a Delayed Surface Marker Buoy (DSMB). In this article we will discuss  a few different ways of how to deploy a Delayed Surface Marker Buoy, using a finger spool reel.

A SMB is used on your dives when you get to the point that you and your buddy decide to go up. First of all, you will want to signal to your buddy that you’re okay, and ready to deploy your SMB. Next you will want to get out your SMB and get out your finger reel. The next step is to attach your finger reel to your SMB. Remember that you may need to unravel your SMB a little bit, so you can get to that attachment point on the base of the SMB. With your finger spool, take out the double ended bolt snap and secure that onto a D-Ring on your BCD or onto your harness system. Remember to make sure that its secure and won’t accidentally fall off and disappear as you will need it again shortly.

The next step is to physically attach the finger reel to the base of the SMB. As there are many types of different models on the market you may need to attach a clip or put the reel leader line through the webbing on the SMB and then pass it back through the hole in the leader line to create a secure connection. Which ever method you need, the most important part is that there must now be a secure connection between the finger reel and the SMB.

Next you will need to unravel the SMB. Remember to take your time here when completing these steps, particularly if you’re a newby, as it is here that many divers rush and create tangling problems for themselves. As with many skills underwater, a slow and methodical approach is best. Just take your time and organise everything, keeping it away from your body and your equipment to prevent accidental snagging.

You are now ready to begin inflating the SMB. This can be done in many ways however if you are new to using an SMB, then we suggest using your Occy/Alternate regulator. Secure your alternate air source, make sure it works and place it on the under side, inside of your DSMB. Give it a small puff of air, just to put some air in. This allows more time to ensure that all steps have been completed correctly and that there are no entanglements. When you are happy you can then fully inflate it and let it go. Remember that the volume of air inside the SMB will expand as it rises, so if you don’t completely fill it don’t worry, physics will do the rest!

Once your SMB has shot up to the surface, keep hold of your reel. You can use the tips of your fore finger and your thumb to hold the reel when it shoots. This way you have some limited control of its speed. Then grab the double ended bolt snap you previously clipped off to the D-ring and now attach it to the line on the reel. By pulling it nice and tight and then attach it to your reel you can use it to easily help you hold the correct position. This will allow you to re-secure your alternate air source. Once done you can now grab hold of your reel and you’re ready to begin the ascent and complete your Safety Stop.

There are many different ways to deploy your Delayed Surface Marker Buoy, using a finger spool. It’s always best to practice your method multiple times in a controlled environment, like a swimming pool or a shallow and sheltered shore diving site, before you go to a deeper open water environment. In addition it’s always best to learn with an Instructor present, so that they can teach you, hands on, exactly how to deploy your SMB.

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