Scuba Diving Safety Equipment FAQ

1. Why do you need additional safety equipment for diving?

Anything you can do to make diving safer is worthwhile.  Diving can be a very enjoyable and rewarding sport but it also carries some significant risk, particularly when you are diving in open waters.  There are a number of hazards associated with diving from harmful marine creatures such as jellyfish through to other water users.  In order to enjoy your diving sessions as much as possible you will need to make sure you have all the safety equipment you need and understand the right techniques and precautions to keep you safe.

2.  How can I communicate underwater in an emergency?

The primary step and often the hardest part of communicating underwater is getting your buddy’s attention. There are various devices used to signal underwater to your buddy alerting them of your desire to communicate. These range from things like, air horns or air hammers that use your air supply to make an audible noise underwater through to simple and inexpensive things such as tank banners and scuba rattles. Once your buddy is aware of your desire to communicate there are then means to communicate using visual hand signals and visual messages. When you do your diver training you will be taught the internationally recognised hand signals that are used by divers to communicate basic messages underwater.  It is important you understand these signals properly before you go on any dives.  You can also use dive slates to communicate more effectively and these are simple devices that allow you to write messages underwater.  Dive slates can also be used to help plan decompression models when you are on a dive.

3.  Why do I need a dive knife?

A dive knife is probably one of the most essential pieces of equipment a diver can carry. Underwater there are many dangers that a diver can face, one of them being entanglement. The oceans are used for many different activities and often items such as fishing line or rope are discarded. Apart from the obvious use as a cutting tool, dive knives can be used for many purposes such as being used to make an audible noise when trying to get your buddy’s attention, striking it on the cylinder. In strong currents, they can be used as a means by a diver to prevent being swept away in a current by digging the knife into the sea bed, similar to how a climber would use an ice axe. In many of the older diving training organisations, a dive knife is considered so essential as to require carrying more than one. Dive knifes will not protect you against underwater predators but they are an essential safety device and can come in useful for a number of other tasks as well.

4. How do I carry items safely when I am diving?

The general rule of thumb whilst attempting to carry items underwater is not to try and physically carry any item heavier than 4 kilograms. Carrying an item weighing more than 4 kilograms would require so much air to be added to the BCD that should the item be dropped a runaway ascent is almost unavoidable. Small items, under 4 kilos, can be carried either in BCD pockets or specifically designed underwater bags, usually made of mesh to allow water to drain and should be secured to the diver. When securing items or bags to a diver, it is necessary to evaluate the environment you are diving in and the possibility of entangling yourself with the bags you are carrying. If you are in an environment that is prone to entanglement such as inside a wreck, it is not advisable to secure bags or ropes to the diver which can lead to entanglement. Items heavier than 4 kilograms should only be moved or carried using lifting bags so as not to adversely affect the buoyancy control of the diver.

5.  What is the safest way to lift heavy weights when diving?

If you are on a technical dive you may need to lift heavy weights from the seabed. This could include items such as outboard motors or archaeological finds.  To help you lift heavy weights safely to the surface you can use lift bags.  These bags have an internal air pocket which can be filled underwater to create floatation devices.  This can then be attached to heavy objects allowing the diver to manoeuvre them more easily to the surface. When filling a lift bag, it is important only too inflate the item enough to become neutrally buoyant and to allow the item to be moved by hand easily by the diver. The lift bag should not be over inflated which could provide so much lift that the item rockets to the surface uncontrollably endangering the diver beneath. 

6. Should I carry additional air tanks?

Air tanks are bulky and you will not be able to carry a full additional tank on a dive.  However it does make sense that you have a backup source of air just in case you run out or anything happens to your main tank.  You can get small emergency air tanks which can be strapped easily to your main tanks.  These are known as pony tanks and can offer a limited supply of air for emergency situations.  These pony tanks often have their own independent regulators and you can completely detach them and use them as an air supply if you are forced to dump your main air tank and regulator. Independent air sources such as pony bottles in some situations such as technical wreck diving cave and cavern diving are considered mandatory equipment as the usual use of alternate air source and the buddy system can’t always be achieved in cramped or tight spaces. Pony bottles would strongly be advised where there is no direct access to the surface such as in wrecks, caverns and caves.

7.  Do I need a marine whistle when diving?

It can be very difficult to spot individual divers in the vastness of the open ocean so anything you can do to draw attention to yourself increases your safety.  It can be too easy to get separated from your dive boat or tour group and a marine whistle is a simple, affordable device that will attach to your tank or BCD.  These whistles are much louder than regular whistles and will work even when they are soaking wet.

8.  Should I invest in a diver signalling device?

Diver signalling devices are important safety features.  Like marine whistles they can help to attract the attention of your dive party if you get separated.  Diver signalling devices emit both light and sound signals and can be used under and above water.  If you get into trouble underwater they can be valuable tools to alert your dive buddy that you need help.

9. Do I need to carry a safety sausage or other means to signal a boat?

Safety sausages or deployable marker buoys in many countries are mandatory equipment. Should a diver surface from a dive a significant distance away from the dive vessel they need a means to draw the attention of the surface watch to their position. A safety sausage is a highly visible flexible plastic tube which can be rolled up and stored easily in a BCD pocket but once deployed and deflated becomes a 2 metre tall signalling device. This high visibility plastic tube can be seen at distances up to 2 kilometres from a dive vessel, far beyond the distance where a divers head would have been lost from sight.

10.  Is there are any special safety equipment needed for wreck diving?

Wreck diving falls into two distinct categories, diving around a wreck where the entire dive is conducted outside the structure of the wreck and secondly where penetration of the wreck is the goal of the dive. For dives that intend to penetrate a wreck, a wreck reel and at least 2 light sources are the minimum requirements and there are also additional items such as directional markers for lines and jump reels that are often used whilst penetrating a wreck. Divers wishing to penetrate a wreck should always ensure that they are correctly trained and equipped to conduct the wreck penetration and reduce the obvious risks involved. Divers wishing to conduct dives around a wreck without wishing to penetrate have to protect their body and skin from the obvious hazards of sharp and rusty edges. It is a good idea to wear boots and gloves (and knee pads) even if the water is warm to help prevent cuts and scrapes. 

11.  What are surface marker buoys used for?

Surface market buoys are essential items of kit for divers.  They are used to alert other water users that there are divers under the surface.  This is very important to avoid any collisions and will also show rescuers clearly where divers are if there is an emergency.  Surface marker buoys will also show the support boat where the divers are which is important during drift dives, night dives and poor visibility sea conditions.