THREE LONG YEARS AGO, I SPENT a frustrating day sitting onboard a dive charter-boat while everyone else (except the skipper) was under water exploring a deep wreck.
All wasn’t lost, however – I was there to research surface marker buoys with diver, skipper and Weymouth Lifeboat cox’n Ian Taylor for a feature (Skipper’s Point of View, July 2011).
The outcome was that a mixture of red and black proved the easiest to see in nearly all conditions found off the UK coast.
It seems that no one read that little piece of wisdom (well, no one that makes marker buoys, at least) – until now, that is.
Maidstone Course Director and technical-diving instructor trainer Ryby Stonehouse saw the need, and has produced a delayed SMB that actually ticks all the boxes.

The Design
What can be said about a DSMB It’s a polythene-lined nylon tube that’s filled with air and sent to the surface from depth while attached to a line on a reel.
Here’s the scary thing: some divers see this bit of kit as an optional extra, when in fact it should be mandatory dive gear.
Ian Taylor has few rules, but this he does say: “If you haven’t got a DSMB, you’re not getting in the water from my boat.” It follows that this is a piece of essential safety kit, and you can’t just pay lip service to something on which you rely for your personal safety.
Ryby has incorporated all the best DSMB features in his design. It has an open base by which air can enter from various sources, such as exhaled gas or purged gas from an alternative second stage.

Once the SMB is inflated, internal pressure closes and seals the base so that it won’t dump air at the surface if it lies flat. Air is exhausted instead via a pull dump-valve that is over-pressure-sensitive and will prevent the DSMB from rupturing as gas pressure increases on
its ascent.
There is an alternative method of filling the buoy, which is via a dedicated tube with a one-way valve that mimics the standard male type of low-presure inflator connector found on drysuits and BCs. This inflation tube doesn’t have a recess, so the lp hose will always slip off as the buoy ascends.
For rebreather or technical divers with bail-out stage cylinders and regs fitted with spare lp hoses, this is said to be the safest option when deploying the buoy.
The colour is the next bit of genius. It’s two-tone, solid black on one side and solid fluoro
red on the other. There’s a webbing loop and small D-ring at the base for reel and line connection, plus a small loop of bungee to keep everything in place when it’s rolled up and waiting to be deployed.
The whole thing measures 2m x 20cm when deployed, and it packs down to just 20cm x 7.5cm diameter and weighs in at a paltry 340g.

In Use
I used this DSMB on a rebreather trip in the Egyptian Red Sea. Rolled up and connected to a stainless finger-spool it took up very little space, and I had it clipped to a spare D-ring during the dives.
When it came to deployment I used my spare low-pressure inflator. I connected it to the inlet spigot, and it took only a small push to add a substantial amount of air in a very quick burst.
The DSMB sped to the surface, expanding even more as the ambient water pressure was reduced. I had never deployed a DSMB in this manner before, and it was by far the easiest method I have used.
On subsequent dives I deployed it using exhaled gas (open-circuit) from my regulator through the bottom opening in the conventional way, and the buoy behaved exactly as it should.
The length of this buoy means that it sits well above the surface, making it even easier to
spot. The black side contrasts well with water reflecting a white sky, while the red side is highly visible against water with a darker surface.
During the photo-shoot I laid it flat and used it as a surface support. It held my weight (admittedly without a scuba unit) and kept my upper torso out of the water.

Why such an important piece of safety equipment has taken so long to evolve into something that’s so fit for purpose is beyond me. Credit has to go to Ryby Stonehouse for this ultimate DSMB.
I will always have one with me, no matter where I’m diving. I know what it’s like to be in mid-channel, set adrift miles from the boat, and it’s bloody terrifying.

SIZE 2m x 20cm
COLOUR Black, red
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