Hanging off a Surface Marker Buoy

I was recently asked by a new diver what my thoughts were on hanging on a surface marker buoy. The question was, should one hang on to the SMB or just keep enough pressure on it to keep it upright on the surface? This is an interesting topic as it would appear that there are benefits to both ways.

The benefits pointed out by the diver was that one could rest while hanging on the SMB and that it ensured the SMB would remain upright, so as to be easily seen by the boat. He went on to add that he liked to use stainless steel spools and felt they were a great invention. Listening to all of this, I felt it was worthy of writing an article and explaining what the team use and our reasoning behind it.

The team always use delrin spools and the small halcyon SMB for the following reasons:

  • Delrin spools will sit mid water while they are being deployed, which is useful if it happens to slip from your pinch grip for some reason.

  • Plastic spools will float up if they slip from your pinch grip while the SMB is being deployed. The result is a lost SMB and spool. Plastic spools also break very easily in pockets.

Stainless steel spools will sink if they slip from your pinch grip, while the SMB is being deployed. The result is a fully unwound spool and a high possibility of line entanglement when you try to get the spool back - or you have to go back down to the bottom of the line and start winding the spool back up. This is neither safe nor practical.

The Halcyon small SMB fits well in a pocket, it can be inflated in one breath and is very easy to deploy. It is ideal for light to medium seas, but for rougher seas, some kilometres out from the coast, a larger closed Halcyon SMB would be a better choice.

To Hang or Not to Hang?

We choose not to hang but to keep light finger pressure on the spool or line as needed to keep the SMB bobbing on the surface. This is done to allow one to be able to be independent of the rolling swell that can throw you up a metre or two if you are relying on the SMB for your position in the water. Secondly, it allows you to practice your buoyancy control and ensure your rig is fully balanced.

When deploying a SMB, the team procedure is to look above to the left and right to ensure you are not deploying on another diver above you.

Another thing that should be considered is that if you are hanging off your SMB and it didn't inflate as much as you intended it to before you let it go, you could very easily drop down a few metres without realising, as you are relaxing and not focussing on your depth. By not hanging on your SMB, you can keep a constant eye on your depth gauge and stay within the range of your deco stop with little or no effort.

My general observation is that those who tend to hang off their SMBs are often (but not always) more vertical in the water column and this makes it a little more difficult to swim over to a buddy and render assistance if an issue arises with them.

SMB deployment can be a team task - meaning that one can hold the spool, while the other deploys the SMB if the team wish to share the task. During deep dives beyond 70m, this is often the preferred method as the SMB may be deployed as the team leave the bottom and this is especially useful if there is a strong current. A primary reel is used in place of a spool for this type of deep deployment.

Generally only one SMB per team (buddy pair or three person team) is deployed. The exception to this is if the team members are practicing deployment. The deco man runs the deco and the SMB man runs the SMB. The deco man stays mid water within touch reach of the SMB man. The SMB man may choose to hand the SMB off to the deco man for a short time while he does his gas switch or stows his primary light. By being in complete control of your buoyancy during the SMB stage of the dive, this handing off and returning is very easy for team members to achieve.

You can also have a little fun with a golf ball and play a little deco golf if you are in control of your buoyancy. Check it out on the Video Page The diver on the left is just keeping light pressure on the top of the spool, the diver on the right is letting the line run through his fingers, the video guy has no spool or SMB and is sitting mid water in control of his buoyancy.

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