There are a variety of signaling devices - Signal lights and flashers, Signal mirror, Delayed Surface Marker Buoys (DSMBs), Inflatable signal tubes, whistles and air horns. Description In the unlikely event that you’re at the surface and need to get the attention of someone on shore or on a boat, you’ll be glad you have a surface signaling device. Signaling devices are important safety equipment that help scuba divers be seen and heard if they need assistance. The recommendation is to always carry at least two devices – one audible and one visual. Visit your PADI Dive Center or Resort to get advice about surface signaling devices. Standard Features Inflatable signal tubes – These brightly colored inflatable tubes – usually orange or yellow – stand more than a metre/yard above the surface to make you more visible. They are required equipment in many areas worldwide and highly recommended everywhere else. They roll up compactly and fit in your BCD pocket when not in use. Delayed Surface Marker Buoys (DSMBs) – Similar to inflatable signal tubes, DSMBs are attached to a line and reel and can be deployed from underwater or at the surface. Signal mirror – By reflecting sunlight with your mirror, you can attract attention and even signal an airplane overhead. A small signal mirror easily fits in your BCD pocket. Signal lights and flashers – Although most effective at night, lights and flashers can also be used to gain attention at the surface. Audible Surface Signaling Device Styles Whistles – A whistle, like the PADI Whistle, is small, easy to carry and effective, which makes it the most common audible surface signaling device. It’s standard practice to attach your whistle to your BCD inflator hose where it’s easy to find if needed. The sound from a two-toned whistle carries a long way over water. Air horns – These devices use air from your tank to make a noise usually much louder than a whistle. There are a variety of different styles available that usually attach to your BCD inflator hose. Because you need air in your tank to use them, it’s a good idea to also have a standard whistle. How to Choose The great thing about choosing a surface signaling device is that you can’t have too many for safety. Considering that you should have at least two – one audible and one visual – you may start with a whistle and inflatable signal tube or DSMB (if required in your area). If you’ll dive in more remote destinations, add a signal mirror and air horn to your kit. Ask the dive professional at your local PADI dive shop about which devices divers use in the local area. Advertisement More Gear Dive Flag and Float Single to boats that there are divers down below with a locally recognized red flag with a white diagonal stripe or the blue-and-white pennant tail.