SMBs, DSMBs & Diving Reels
Being visible to your boat crew and other surface users is an important part of planning a dive. Surface marker buoys (SMBs), delayed surface marker buoys (DSMBs) and diving reels help divers communicate their position and support a controlled, well-planned ascent.
At Sussex Diving, we offer a range of SMBs, DSMBs, finger spools and diving reels suitable for recreational, boat, drift and more advanced diving.
SMBs & DSMBs – What's the Difference?
A surface marker buoy (SMB) is generally deployed at the surface to identify a diver's position. Some designs are intended to be towed during a dive.
A delayed surface marker buoy (DSMB) is designed to be deployed from underwater, allowing divers to indicate their position to surface support before ascending.
DSMBs are particularly useful during UK boat diving, drift diving and dives where the surface crew needs to identify a diver's location.
Choosing the Right DSMB
DSMBs are available in different lengths, colours and inflation configurations.
Common features include high-visibility materials, oral inflation tubes, low-pressure inflator connections and over-pressure relief valves. Features vary between models.
The most suitable design depends on your training, diving environment and how you intend to deploy the buoy.
Finger Spools – Compact & Practical
Finger spools provide a compact way to carry line for deploying a DSMB.
Their simple construction makes them popular with recreational and technical divers, particularly where a lightweight, easily stored solution is preferred.
Spools are available with different line lengths and may be supplied with a double-ended bolt snap for secure storage.
Diving Reels – Additional Line Capacity
Diving reels offer a larger line capacity and different line-management arrangements compared with compact finger spools.
Depending on their design, they may be used for DSMB deployment or specialist diving activities requiring a managed line.
Choosing between a spool and reel depends on the intended application, required line length and your familiarity with the equipment.
Visibility, Line Length & Ease of Use
When selecting an SMB or DSMB, consider how easily it can be seen at the surface, particularly in changing sea conditions.
Bright colours, suitable buoy dimensions and appropriate inflation arrangements are all worth considering.
For reels and spools, consider line length, handling, storage and compatibility with your DSMB.
Equipment should also be manageable when wearing the gloves you normally use for diving.
A Delayed Surface Marker Buoy (DSMB) is an important piece of diving equipment, particularly for UK boat and drift diving. However, knowing how to deploy it correctly is just as important as owning one.
Good technique helps you manage your buoyancy, control your reel or spool and deploy your DSMB without becoming entangled in the line. These are skills worth developing and practising under the guidance of an experienced instructor.
At Sussex Diving, our PADI DSMB Specialty course provides practical training in DSMB selection, preparation and deployment, helping you develop the skills to use this essential equipment effectively.
Explore Our PADI DSMB Specialty Course →Practical Equipment Advice from Sussex Diving
As a family-run PADI 5* Dive Centre in Selsey, West Sussex, we're familiar with the equipment requirements of UK shore and boat diving.
Whether you're purchasing your first DSMB and spool or upgrading your existing equipment, we're happy to offer straightforward advice on the options.
Not sure which setup is right for you? Visit our Selsey dive centre or contact the Sussex Diving team for friendly, practical guidance.
