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Our dive team regularly get asked about the dive kit they use and what made them choose it. Here is the next instalment of our ‘We Recommend’ feature, discussing our choice of DSMB.


One piece of dive kit that I use regularly is a DSMB and spool. For those who are new to diving DSMB stands for ‘Delayed Surface Marker Buoy’. When diving in the UK, be it from a boat or from the shore it is highly recommended and in some cases absolutely required, to have a DSMB while diving.

When deployed just before or during an ascent the DSMB and line provide a reference to the surface for the diver and mark your position on the surface. This can really help your ascent, especially if you’re ascending mid-water, by providing a reference. It also warns any boats that are in the area to keep clear of your position and can let your dive boat know you’re on the way to the surface.

There are various features and options when choosing a DSMB and spool which we will talk about today. The DSMB I use is a Tecline semi-closed buoy. It is bright orange in colour, 122 cm high and 18 cm wide which means it is highly visible, even in the sea with some swell. It rolls up into a contact shape and is secured with the supplied bungee and clip.

Tecline DSMB

One of the top features of this DSMB is the metal inflator valve, allowing the buoy to be inflated using your drysuit inflator hose. This is highly advantageous in cold UK waters where using the purge button on your alternate air source could cause the regulator to freeze up and free flow. This inflator valve is very robust and simply designed making it easy to use.

tecline DSMB metal inflator

This buoy is semi-closed, which gives flexibility and options when inflating. On the inside and bottom of the DSMB there is a flute which directs the gas into the buoy and as the buoy fills up that entrance seals up so the gas can’t escape. This feature makes the DSMB flexible, as it can be inflated using exhaled bubbles or a regulator second stage in warmer water in addition to through the inflator valve.

Hidden Depths Spools

The DSMB needs to be paired with a form of reel or spool to carry line. Discussion of spools versus reels is certainly a blog topic for another day! Personally, I use one of our 35 m aluminium spools. These spools come in four different colours – black, blue, red and purple. They have 35m of white line which is a very practical length for divers doing a maximum of 30 m dives.

One reason I prefer a spool is that it’s very compact, and when coupled with our Tecline DSMB, it will fit nicely into a drysuit pocket and stowed away until needed. Spools also have no moving parts which make them difficult to jam and very reliable to use.

In summary, we highly recommend the Tecline semi-closed DSMB together with our own 35m spool because it’s a compact, simple package that is reliable, flexible and easy to use. We stock both the DSMB and spools and are happy to show you all the features discussed in this blog. If you want any advice on using a DSMB we also offer the PADI Delayed Surface Marker Buoy course, which will give you lots of practice and confidence using this vital piece of kit.


Written by Jason Gritter, PADI Open Water Scuba Instructor and Inspiration CCR Diver

Want to Join The dive Club?

How to join

Our dive club membership runs annually and is renewed every January.

To sign up for the dive club all you need to do is submit a trip liability form along with your club membership fee of £35.

You will receive a short questionnaire which asks about your diving qualifications and important information like emergency contact details, and then you’re signed up.

Updates are sent out through email, and you will have access to our members-only Facebook group which is ideal for arranging dives with other club members.