When you are at the surface or close to it, you will want others such as boaters, and of course your dive boat to be able to see you. Even a few years ago, only a small percent of divers would ever use a surface marker buoy (SMB). Today, it is an accessory that every diver should own. The increasing acceptance and even the need for a surface marker buoy have caused the current training standards for Open Water Divers to include the use of an SMB as a critical task.

The SMB we will be reviewing is the type that is alareso called safety sausages. These are small fabric or nylon tubes that are rolled into a small compact item. At the surface, you add air, and they expand into a highly visible buoy that stands above the water. A Delayed Surface Marker Buoy (DSMB) is a similar item but has a line and a reel attached and are deployed before the diver surfaces. Some items marketed as an SMB are also used as a DSMB.

 The SMBs on our list will keep you safe when you are in the water. Here are our top 10 for 2023.

Pro tip 1 - Closed-Circuit vs. Open-End SMBs
  • Closed-circuit SMBs can be inflated and released without the risk of losing air in high-current or turbulent conditions. Open-ended SMBs are most practical in calmer conditions. 
Pro tip 2 - Inflation Method
  • Instead of taking your regulator out of your mouth to inflate your SMB, use your second-stage regulator’s purge valve to inflate. This method allows the diver to continuously breathe, keeping their buoyancy consistent and neutral. 
Pro tip 3 - Line 
  • When inflating and releasing your SMB, it’s crucial not to get entangled in the line. Using a high-quality line will ensure that the line does not twist or tangle in the reel, making the smoothest release possible.

Scuba Diving Expert

How To Choose A SMB For Scuba Diving – Buying Guide


A diver that has a surface marker buoy and knows how to use it is safer. A certified diver is well-trained to take care of themselves and their dive buddy underwater. However, they have no control over what others are doing on the surface. Having an SMB or a DSMB and knowing how and when to use it, will help keep them safe from harm from surface traffic, as well as helping the dive boat crew keep track of them.


If people are going to be able to see you, the dive marker will need to stand out. Most are bright red or orange with options for yellow or green. The color is mostly one of choice, however, you should consider the color of the water you are diving in. If you are night diving (which you really must try), then having the means to attach a light or chem-stick is a must.


A surface marker buoy must be small enough when not in use to be easy to carry and out of the way. On the other hand, when they are inflated they need to be seen from a distance. 

Full-sized markers will range in size from 4 to 8 feet in length and 4 to 12 inches in diameter. We find that 6 feet is the sweet spot. Anything smaller will be hard to see in rough sea conditions. Larger ones will add a great deal of bulk when not in use and add little when in use. If you are diving in calm water and are mostly concerned with boat traffic, a 4-foot length should still perform well.

Closed-Circuit vs. Open-End SMBs

When you are looking at an SMB, you will notice that you have two options: closed and open-end. The two options are what you would expect from the name. The open-end SMBs have an open end. This makes them easier to inflate. The open end will weigh to keep the open end under the water. If the end does breach the surface of the water, then the air will escape, and they will be flat on the surface and maybe even sink. Closed-end SMBs have a valve to keep the air in. Once they are inflated, they are easier to keep inflated. As with many things, the type of SMB you buy is a personal preference. Try both styles and find out which you are more comfortable with.

Inflation Method

One thing we like about the open-end SMBs is that they are easy to inflate. You can use any source of inflation to put air into it, but one handy way to inflate them is to purge your octopus. Pressing the purge button causes the octopus (backup regulator) to free flow air. It only takes a few seconds and you can position the SMB where you wish as it fills.

For the closed SMB, you may have two methods to inflate it. Most will have an oral inflation tube. You exhale into the valve to inflate it. This generally involves taking in a breath through your regulator, taking the regulator out of your mouth, and then exhaling into the marker. A second option on some surface marker buoys is a connection for a low-pressure hose. You disconnect the low-pressure hose from your power inflator and connect it to a similar port on the SMB.

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A true SMB is inflated at the surface and you simply hold on to it, so no line is needed. However, an SMB used as a dive float or a DSMB will need to have a line that the diver holds or is attached to his BCD. Lines should only be attached after the device is at the surface. In most cases, a DSMB is released while the diver is at the 5-meter safety stop. When used in this manner it alerts boats and your dive boat crew where you are. When you ascend, you do so in a manner that you surface next to the marker. Used in this manner, you will just need enough line to reach the surface plus a little more for current drift. When you are using an SMB as afloat such as when you are drift diving, you need a line that is 10% longer than your planned dive depth. A spool or reel is recommended.



Q: What Is A Surface Marker Buoy?


A surface marker buoy is normally referred to as an SMB. It is a safety device to make you more visible to surface traffic. A delayed surface marker buoy is very similar, however, it is launched while you are still under the surface and has a line that one end stays with the diver. This is generally done at the safety stop before you ascend.  Both an SMB with a line and a DSMB can be used during drift dives.

Q: Why Do I Need A SMB?


There are even some destinations where an SMB is mandatory for a diver. Boating regulations require boats to maintain a distance from divers in the water. An SMB identifies to boaters the location of a diver. They can also be important to help your dive boat find you if you surface away from them. It is hard to see ahead in the water even as close as 50 feet.

Q: Open At The Bottom Or Self-Sealing SMB?


The choice is entirely up to you. The open-bottom SMBs are easier to inflate, and you do not need to take your regulator out of your mouth to fill them. You will need to do a little more work with a closed-end SMB, but once they are inflated, they will stay inflated, and be easier to use. The section above goes into more detail.

Globo Surf Overview

It is a very sad fact that each year divers are injured and even killed being struck by boats and jet skies. Often the operator failed to see the diver in the water. Divers using an SMB or DSMB are more visible to surface craft. There is also a growing worldwide education initiative to ensure surface craft operators know what they are used for.

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