A Dummy’s Guide on SMB’s and DSMB’s and How to Use them

Introduction to SMB’s and DSMB’s

If you’re an avid scuba diver, having the right equipment is crucial for a safe and enjoyable underwater experience. Among the essential gear you’ll need is a Surface Marker Buoy (SMB) and / or a Delayed Surface Marker Buoy (DSMB). These buoyancy devices serve as signals to indicate your location to your dive partner or boat on the surface, as well as alert passing boats to your presence. In this article, we’ll provide a comprehensive overview of SMBs and DSMBs, including their uses, features, their pros and cons, safety considerations, and maintenance tips. Whether you’re a novice diver or an experienced one, read on to discover how SMBs and DSMBs can enhance your diving adventures.

SMBs vs DSMBs – Understanding the Differences


A Surface Marker Buoy, or SMB for short, is an inflatable buoy used to indicate your location to the surface team. It can be towed throughout the dive and is deployed at the surface. SMBs are often referred to as “safety sausages” and are crucial for maintaining visibility during the dive.


On the other hand, a Delayed Surface Marker Buoy, or DSMB, is an inflatable buoy used to mark your location while submerged. It is deployed at the end of the dive, typically during ascent or on the safety stop. DSMBs are larger and more visible than SMBs and often come with a reel for easier deployment and retrieval.

Understanding the distinctions between SMBs and DSMBs is vital for using them effectively and ensuring your safety during a dive.

Features of SMBs and DSMBs

Various types of SMBs and DSMBs are available, each with its own features and advantages. Let’s explore some common types:

Open-ended SMBs:

These SMBs have a single opening at the bottom, allowing air to escape freely from the top. This design makes them easier to inflate and deflate.

Closed-ended SMBs:

Closed-ended SMBs feature a one-way valve that enables air to be added but not released. This design makes them more buoyant and visible underwater.

Self-sealing SMBs:

Equipped with a self-sealing valve, these SMBs prevent air from escaping, making them easier to use and maintain.

Colors of SMBs and DSMBs:

SMBs and DSMBs come in a range of colors, each with its own benefits. Bright colors like yellow, orange, or pink are highly visible and easier to spot from a distance. Some SMBs and DSMBs also feature patterns or SOLAS reflective tape for enhanced visibility.

Reels, SMBs & Buoys

Are you Looking to Buy an SMB/DSMB and reel?

Oyster Diving Shop has a range of SMB’s and DSMB’s for you to choose from. All of our staff are professional divers and are also on hand to offer you advice. Spend over £100 and you can even try it in the pool for free!