Signaling Devices


Once you have assembled a basic set of kit together there are so many different bits and pieces you may want to get, some of it is very useful and other bits are more for specialised types of diving such as wreck diving or cave diving. If you want to add to your collection then the best gear I would recommend is getting yourself some safety equipment! It may seem like a good idea to buy a big knife to strap round your leg but will not really be of much use to you (although knives are still part of your standard equipment set up).

Surface Marker Device

The most important thing I can think of is getting some sort of surface marking device. This in my opinion is the most important thing to take on every dive, and use it on every dive. These come in 2 forms. Depends on where you dive depends on which type you will use. The first is called a Surface Marker Buoy, or sometimes referred to as a dive float. These are usually ring shaped, and are deployed right from the beginning of the dive, connected to a line which the diver takes around the dive site with them. These are commonly used in drift diving situations, where the dive boat usually follows the float and picks them up after the dive. Another use for these are in areas where these are used are in areas where there is high amounts of boat traffic. In fact many parts of the world have laws to ensure divers keep these on them at all times, with one of the dive flags flying so boat and other watercraft know to keep well away from them. The downside of this type of surface marker is that you have to keep hold of the line throughout the dive. It is very important that you never attach the line to yourself, in case it gets caught on something.

The more commonly seen surface marker is called a delayed surface maker (DSMB) although they are commonly referred to as an SMB as well. This is an inflatable tube that is kept on the diver over the dive and then deployed at the end by inflating it with either the alternate air source, exhaled air or very occasionally they have a small cylinder attached which is used specifically for filling the DSMB. The diver also needs a line of some sort to keep hold of it as it ascends. The usually have a ring so you can attach a spool or reel of some sort, but some have a line or webbing material already attached. These are normally deployed on the safety stop although some divers prefer to send them up just before, so they can get more air into them. When deploying these it is very important to ensure the line is not caught on you anywhere, as you could end up getting pulled up to the surface at quite a speed. You should take a surface marker with you on every dive. Some parts of the world have a large amount of boat traffic, deploying one of these before surfacing allows boats to see you well in advance and know to keep away. Also if you get lost, separated from your dive buddy, or caught in a current it will allow the surface support to keep track of your location before you get too far away. Also if you are diving in a large swell it can be very difficult for boats to easily spot you. An SMB fully inflated will stand an extra 3 to 6 ft. out of the water, making it easier for you to be spotted.

Whichever type of surface marker you choose, it should be brightly coloured so it sticks out against the colour of the water. They are normally orange/red although you often get them in yellow too. The yellow ones are often used for emergencies by technical divers.

Other Signaling Devices

As well as having a visual signalling device you should also have an audible one. For the surface this is simple, just a basic whistle will do. This can be clipped to your BCD and hopefully you will never need to use it, but it is better to have it there than not having it when you need it! When you are underwater an audible signalling device is nice to have too, especially if you see something really cool and want to get everybody’s attention, or if get separated from your buddy in bad visibility you can just follow each other’s sound. You can buy a special rubber band that fits around your tank cylinder with a piece of hardened plastic attached to it. To make a sound you just need to pull the band and the elastic makes the plastic bang against the cylinder making quite a loud noise. These normally don’t cost much but an even cheaper, and more functional option is just using a single or double ended sliding gate clip (dog clip). You can use these to attach any spare equipment you may be carrying, and all you need to do is reach around and bang your tank cylinder to make a loud noise. Just one important point, please don’t go around dive sites making too much noise as it will annoy the other divers and scare away all the fish!

Learning how to properly use signalling devices is a very important skill for safe diving, and one that many divers overlook as they expect the dive leader to always take charge. And before using them in the open water after a deep dive it is a good idea to practice in shallow water first so you don’t mess it up! Safe Diving!!

‘Signaling Devices’ was written by Mike