Intermediate 8 minutes
Safety equipment: what you carry and hope not to use
SMB, whistle, line cutter and flashlight: small, cheap and decisive
A diver at the surface, with their head poking out among half-meter waves, is practically invisible from a boat two hundred meters away. With a deployed buoy a meter and a half tall, you're visible from much farther. That difference costs little money and takes up one pocket.
In this article you'll see the safety items worth carrying, exactly what each one is for, how to position them so they're accessible when needed, and why most of them are much cheaper than their usefulness would suggest.
This is the equipment you don't use in ninety-nine percent of dives, and that decides the outcome of the remaining one percent.
Getting seen at the surface
Most serious situations in recreational diving don't happen at the bottom: they happen at the surface, when someone can't find the diver or the diver can't find the boat.
The delayed surface marker buoy (also known by its abbreviations SMB or DSMB) is a highly visible inflatable tube deployed from the water. Its function is twofold: signaling your position to the boat and warning marine traffic of divers ascending.
There are two distinct uses. Deploying it from the surface, once you're already up, is simple and requires no special training. Deploying it from depth, typically before starting your ascent, requires a reel or spool and a specific technique: it's a maneuver with real risks (entanglement with the line, an uncontrolled ascent from holding onto the buoy) and it's worth learning with instruction, not improvising it.
The whistle is the simplest and most effective acoustic accessory, and many BCDs come with one built into the inflator. It works at short distances and loses effectiveness against the wind. Sound devices powered by cylinder gas have much greater range.
The signal mirror, which seems like an outdated item, remains remarkably effective on sunny days: a flash can be seen from a considerable distance, much greater than a whistle's.
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