You’re at the dive center, ready for your very first ocean dive. You stand clutching your mask, snorkel and fins like a kid clutching his lunchbox on the first day of school. You are excited and nervous because all night you’ve been thinking about what it will be like once you’re underwater. Here are some of the most common sensory experiences the first time you go scuba diving.
Oh, what big eyes you have…
Underwater objects that are nearby will seem 33 percent larger and 25 percent closer to you than they actually are. Keep this in mind when you’re reaching for the buoy line. This might also make you believe that you’re closer to your buddy than you actually are.
Because of how water absorbs and scatters light, you’ll probably lose some of the finer details, especially of objects further away. This also tends to make objects in the distance look like they’re even further away than they are.
What you see is not what you get
Perhaps you fell in love with the beautiful, vibrantly colored coral that you saw on a documentary and you want to see it in real life. New divers are often disappointed when they see a coral reef for the first time, thinking that it would be as colorful as they saw on television. Although it is, of course, colorful, as you go deeper, colors start to fade until everything looks blue/green. This is called the Tyndall effect. Camera equipment has special settings and light filters (often red) to compensate for the change in light and color.
With time you will learn the color spectrum as you see it underwater and be able to identify different colored-corals based on their subtle differences. Some people dive with a flashlight on every dive to see the color of the coral as you would on land.
Everything isn’t always crystal-clear
Once you get used to the feeling of your mask on your face you tend to forget about it and it becomes an extension of your body. That is, until either water leaks in or your mask keeps fogging up. Here are some tips for easy mask clearing.
It is all around
Once you enter the water you will soon realize that the action is happening everywhere. Your buddy can be in front of, next to, or behind you. And spotting marine life becomes a bit of a treasure hunt as it often hides in crevices or under rocks. Look behind you, to your left and right and above for passing animals.
Because you spend most of your dive horizontal, in a space with less gravity than on land, you might find that things are not where you expect them to be. The power inflator hose for your BCD, for example might be floating by your left ear if you didn’t strap it down
When looking and feeling becomes touching
In an environment where touching is discouraged, we often use our eyes as a substitute. We can see when something might feel soft and squishy (like bubble coral or sea cucumbers) or hard and spiky (like staghorn coral or sea urchins).
Although you cannot touch with your hands, your body comes into contact with many different stimuli. You’ll notice the change in water temperature and pressure, the wetsuit on the skin and the movement of water against your exposed skin. Eventually divers become so accustomed to touching through seeing that it feels almost alien when they do touch something, like accidentally drifting into a rock or your buddy.
Increased pressure
When you are underwater you feel free and weightless because water is denser than air and thus it supports your weight more than air does. As the water ‘holds’ you it enables you to move freely in all directions.
This increased density also exerts more pressure on your body and airspaces. Unlike on land, divers experience pressure changes constantly. Moving only a few feet deeper or shallower will influence whether you will need to equalize or adjust your BCD. With experience you will learn to adjust your position in the water by making small adjustments to the air volume in your lungs.
Hearing
Sound waves travel much faster underwater than in air. This means sound seems to be coming from everywhere at once. This can of course confuse and disorient you, as you cannot tell where it’s coming from.
As external sounds drift to the background, you become more aware of the noises your body makes. Breathing in-and-out through your regulator makes you sound a bit like Darth Vader. You no longer hear your bodily sounds through the air but rather through vibrations in your bones. You might become aware of the sound you make when you swallow and the slight ticking that occurs when you equalize your ears. And although the underwater world may seem silent, if you focus and pay attention as you swim over a reef, you’ll hear the sound of countless creatures munching happily away on coral and algae.
