The Ultimate Guide to SMB & DSMBS for Scuba Divers

The Ultimate Guide to SMB & DSMBS for Scuba Divers

Are you a new scuba diver? Have you recently started exploring the mesmerizing blue depths of the oceans and seas around the world? Then you must understand SMBs (Surface Marker Buoys) and DSMBs (Delayed Surface Marker Buoys). Although both carry out similar functions, their uses have distinct differences. In this comprehensive guide, we will discuss different types of these marker buoys and the type of colours available in each one to meet your diving safety needs. So if you want to know more about SMBs and DSMBs for scuba divers, read on!

Why do we use SMBs and DSMBs?

As divers, we know that safety is a top priority. That's why we use SMB or DSMB during our dives. An SMB (Surface Marker Buoy) is an inflatable marker we deploy at the water's surface to signal our location to boats and other divers. It's an essential tool to ensure that boat knows our position and can avoid any potential accidents. On the other hand, a DSMB (Delayed Surface Marker Buoy) is attached to a reel and can be deployed at any depth during the dive. The DSMB alerts boats and divers to our location when we ascend to the surface, reducing the risk of collisions. With these tools, we can enjoy our dive with peace of mind, knowing we are taking the necessary precautions to ensure our safety.

DSMB deployed in the Red Sea Decompression Stop

Photo: DSMB Garden, Divers on Decompression, Brothers Islands, Red Sea.

What types of SMBs and DSMBs are out there?

In the diving and research communities, SMBs and DSMBs play an essential role in marking positions and increasing safety of buddy teams working underwater. These inflatable buoys come in various types, each with unique features and use. For example, towable inflatable SMBs are perfect for marking the position of a research team or a freediver while spearfishing. Surface SMBs, on the other hand, are used for marking divers' location or emergencies and can be easily inflated on the surface. Lastly, diving DSMBs are designed to be deployed underwater using a spool or reel and are primarily used for marking a safety stop or decompression. Regardless of the type, SMBs and DSMBs are essential tools for any scuba diver who wants to ensure their safety and the safety of those around them.

When purchasing an SMB or DSMB for freediving, spearfishing, recreational or technical diving, it is important to make sure that the buoy features a reliable and robust valve and high-quality fabric. A quality DSMB inflation valve should be made from durable materials. Additionally, a high-quality DSMB should have SOLAS tape or similar reflective tape and designated mounting points for strobes or positioning lights to ensure the visibility of the buoy on the surface in low-light or night conditions. All of these elements combine together to form an essential part of safe diving practices.

All Types of Diving Surface Marker Buoys
Tow Buoys and Floats Surface SMBs DSMBs

Mares Pure Instinct Buoy Torpedo SF

Mares Torpedo Buoy

Mares Standard Marker Buoy

Beaver Round Surface Marker Buoy

Mares Pure Instinct Buoy Torpedo SF

Tauchsport Tec Buoy Deluxe DSMB

IST QD Mini Delayed SMB

Mares XR SMB

Apeks Surface Marker Buoy

AP Valves Self-sealing SMB's with Inflation Cylinder (with crack bottle)

Colours of SMBs and DSMBs

The colours of SMBs and DSMBs hold great importance in the world of diving. Red SMBs play an important role as location markers, providing information about a diver's whereabouts to marine boat captains and surface traffic or surface support team. Its vibrant hue stands out against the water, making it easily visible from afar. Bright Yellow SMBs, on the other hand, are mostly reserved for emergencies and serve as a cry for help from advanced or technical divers who cannot ascend to the surface without assistance. Black SMBs, much like the red ones, also serve as location markers but are said to be particularly effective in bright daylight. Lastly, multi-coloured SMBs are designed to stand out more in different weather conditions, ensuring the diver's location is easily identifiable. With such a diverse range of colours available, SMBs and DSMBs serve as crucial tools for divers everywhere. 

  • Hi Vis Orange DSMBs
  • Hi Vis Yellow Emergency DSMBs
  • Multiple Colours visible in different weather conditions - Black or Pink 

All colours of SMBs and DSMBs

Different inflation methods for SMBs and DSMBs

For a beginner diver, navigating the world of inflation methods for your float or surface marker buoy (SMB) can be confusing. One popular option is the oral inflation valve, which allows quick and easy deployment with just a few quick breaths. Alternatively, you can choose an open-end regulator inflatable or a low-pressure inflator, depending on your preferences and experience level. An SMB equipped with its gas cylinder, known as a "crack bottle," is another excellent option for easy deployment, but it's worth noting that it may be heavier and more challenging to travel with due to airline restrictions.

Mares XR Delayed Submersible Marker Buoy

  • Orally inflatable towing buoy or floats
  • Regulator inflatable / open end DSMBs
  • Orally or Low Pressure Hose inflatable DSMBs

Different deployment methods for DSMBs

While inflating SMB is easy with your regulator you you need some skill to deploy DSMB. When deploying your DSMB, you have two methods to choose from. You can deploy from a spool, which package takes up very little space and can easily fit in your BCD or drysuit pocket, though it can be fiddly to use in thicker gloves. Alternatively, you can opt for a reel or ratchet deployment, which is more comfortable for beginner divers and allows for easy DSMB release. Whatever method you choose, you must feel confident and comfortable with your SMB to ensure a safe and successful dive. Check with your local dive school or instructor regarding DSMB deployment workshops.



We're Here to Help

If you need help choosing the right SMB or DSMB for your diving adventures, please email us at, where we have a team of scuba diving professionals here to assist you in making the right decision on equipment options. Or, if you live locally or in the surrounding areas of London, pop in and visit us in-store, where you can discover a wide range of diving accessories for yourself and get a feel of which styles you like best.