Author Topic: When should the surface marker buoy (SMB) be deployed?  (Read 2555 times)


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It depends on the situation.

Key functions of the SMB - To let people (and boats) know that there are divers near the surface, and especially to let your boat crew know your location before you actually surface.

To find out more -

There's also a demo video on how to deploy an SMB.


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This is my experience, normally during open water or AOW courses, because you are diving at very calm condition, normally DM or instructor deploy SMB during the 5 meter safety stop.

There are 2 reasons to deploy SMB, one is to avoid been crashed by boat, and secondly is to allow boatman to see you. For reason one, deploy at 5meter is fine, because you are not likely to dive in the path of Tanker nor big cruise ship. But for second reason, you want to deploy SMB as early as possible, see my explanation below:

From my experience it is better to deploy SMB whenever you decided to ascent, especially important when you are diving at challenging conditions, where surface wave is high, strong current or drift diving, you want the boatman to see your SMB as early as possible, because you could be drifted very far away after the 3 minutes safety stop. As long as the captain see your SMB, he will be able to track and locate you even after you are drifted far away.  Especially when you are diving with small boat, when there is strong current and 1 meter surface wave, if you are drifted half to 1km away, the boatman will not be able to locate you, on the other hand, if your SMB is raised near the boat, the boatman can track and know to find you.

There is no disadvantage of releasing SMB early, except that you work more to reel back the line.