One of the greatest appeals of diving comes from the diversity of environments that can be explored – rivers, lakes, quarries, ponds and, of course, the ocean. Each offers its own specific characteristics that make the diving experience unique. Weather, climate and season affect environmental conditions, so your dive experiences at a specific site will vary depending on the time of year.


As a diver, it is very important that you think about water temperature and the suitable insulation to wear for the water. The water temperature will vary according to where you are, what time of year it is and, to some extent, what the weather is like on the day. Wetsuits (also known as “exposure suits”) are what keep a diver’s body temperature at a comfortable level. In addition to keeping divers warm, a good exposure suit also protects divers from cuts, abrasions and stings that sometimes happen during a dive.

Water temperature often changes with depth and usually gets colder the deeper you go. Sometimes, water actually forms very distinct temperature layers. If the water is calm, you can be swimming in warm water and stick your arm out into distinctly colder water. This is known as a thermocline. Thermoclines are found in both fresh and salt water.


Visibility influences your dive significantly, so it is usually one of the first things you want to know before going on a dive. During your beginner’s course, you will learn how to avoid reducing the visibility and how to measure if it is too poor.

Underwater visibility is based on how far you are able to see horizontally. It ranges from 0m to more than 60m. Factors that influence visibility are water movement, the weather, suspended particles and bottom composition.

In limited visibility, it can be difficult to stay with your buddy and keep track of where you are and where you are going. You may even feel disorientated when you are unable to see the bottom or the surface of the water. To handle these concerns, you may decide to cancel the dive or if you choose to dive, stay closer to your buddy than you might usually.

Water Movement

Currents are mass movements of water occurring in the ocean. Temporary currents are caused by winds, unequal heating and cooling of the water, tides and waves.

When you have a current pushing against you, you need to learn techniques to avoid getting breathless and tired. This will ensure that you do not use up your air too quickly.

Bottom Composition

A site’s bottom composition determines the life you’re likely to see and the visibility you can expect.

You will spend most of your dives near the sea floor as that is where all the action is. Bottom composition can be categorised as silt, mud, sand, rock, coral and vegetation. All of these harbour aquatic life and offer interesting diving. Regardless of bottom composition, it is essential that you master buoyancy control, as stirring up the bottom composition may reduce your visibility dramatically.

The Reef Ecosystem

As a qualified diver, you will interact with fascinating underwater creatures and organisms. Some will swim up to you curiously, while others will flee in your presence. Interactions with these creatures should be passive, as approaching aquatic animals can cause them to alter their behaviour and the natural rhythm of their lives.

The vast majority of creatures are timid and harmless, although there are a few organisms that you should be careful of, such as sea urchins and corals. It is easy to avoid being harmed – watch what you touch and wear protection from accidental contact (wetsuit, gloves, etc.).

Animals that seem aggressive (eels and stingrays) are most probably frightened animals that react defensively. Most injuries involving aquatic life result from human carelessness. It takes only a little bit of understanding and care to avoid potential problems.

The reef ecosystem is made up of aquatic plants (phytoplankton, algae, etc.), invertebrates (worms, zoo planktons, corals, etc.), fish, reptiles (turtles, sea snakes, etc.) and mammals (seals, dolphins, etc.). All these parts come together to form a most spectacular scene for you to explore!

Protecting the Underwater Environment

There are a few things divers can do to ensure the protection of the underwater environment:

– Dive carefully to protect fragile aquatic ecosystems.

– Be aware of your body and equipment placement when diving.

– Keep your dive skills sharp through continued education.

– Avoid touching, handling or feeding aquatic life.

– Understand and respect underwater life.

– Do not collect souvenirs like corals or shells.

– Respect the underwater cultural heritage.

– Report environmental disturbances or destruction.