Man is designed to live on land. Sight, hearing, smell, taste and touch are all designed to
work on the surface. Try sticking your head underwater with no mask or snorkel.

What can you see? Yes you can see but it is not very clear, the human eye has not been
designed for seeing under water. With a mask there is a marked difference on the ability
of the eye to see but it does create a tunnel vision effect. Also rays of light that strike the
glass in the mask may be reflected and also reduce vision.

What can you hear? Yes you can hear and sound travels very well in water. However
communication is difficult because it isn’t easy to speak clearly underwater without specialised equipment and therefore hand and rope signals are essential.

What can you smell and taste? Without a mask on you had better not try to smell
underwater. You will find water being sucked up your nose and the end result could be
disaster. Smell and taste are closely related. For the diver the only smell that is
experienced is that coming from the breathing set. You may detect impurities in the air
mixture and possibly experience a metallic taste, this may be an indication of nitrogen
narcosis and if you smell or taste anything unusual it is best to abort the dive and clean
out the breathing set.

What about touch? As the other senses decrease touch becomes increasingly important.
Eventually it may be the only sense remaining that is functioning at any useful level. The
diver must learn to recognise parts of his equipment by touch only and be able to locate
each item quickly and operate it effectively. You can be diving in conditions where
visibility is really impaired and touch is basically all you have.

Pay particular attention to your senses when you begin to dive. Try judging distances
underwater, practice finding essential parts of your diving gear with your eyes close,
using touch only. It pays to become as familiar as possible with how your senses are
affected by being underwater while you are in a relatively safe environment and with
companions who are there to assist and teach. Take turns practicing. Learn your hand
signals they are extremely important and should be second nature to you.

Keep safe and enjoy your diving.

Rex Reservoir - ex diver and submariner