To dive off a tropical coral or a rocky reef makes the majority of diving experiences for scuba divers around the world. There is a dumbfounding array of marine life that is found on many reefs, and that offers a chance of thrilling encounters.

Even though these ecosystems seem to be robust, and bustling with life and movement, actually they are quite delicate, so you must be very cautious with your approach when you explore a reef.

Coral reefs can be very vulnerable to your touches or scraping. A reef consists of a whole bunch of tiny creatures called polyps, which are coated in a kind of protective layer. If you take off this layer by physical contact, it exposes the polyp to infection and the risk of death or disease. Even rocky reefs are subject to destruction as even seemingly bare rocks can be colonized by tiny microscopic organisms, which can be killed or removed even by slightest touch.

Here you find a list of rules to follow at the time of diving off a reef:

Never touch the reef

If you have to balance yourself and there is no other choice, use a single finger and find a more or less bare patch.

Do not shine flashlight into crevices or cracks

To be dazzled by a flashlight is very distressful for marine life, and any occupants are there for a reason, do not forget it.

Take time to explore one spot

Even though there are larger and more charismatic creatures are elsewhere and are seemingly more appealing, take your time to study the smaller reef creatures.

One of the most evocative images in diving experience is the ghostly appearance of a wreck. It is a combination of mystery, adventure, as well as large gatherings of marine life. Each wreck has its own story of tragedy, skullduggery, incompetence or heroism. It is an irresistible draw for divers who have thirst for exploration.

Wrecks are man-made, yet for marine creatures they offer vast flat surface capable of colonization, and its crannies or nooks are used as ambush points or hiding places. Small fish are drawn there to feed on crusting organisms or algae, and as a result, large predators go there for a meal, so the profusion of all kinds of life around a wreck can be extraordinary indeed.

Safety considerations for wreck diving

If dived from the outside, wrecks are safe enough, no more dangerous than an angular reef. Yet if you want to penetrate them, it can be a hazard. The interior can be confusing, visibility is poor, and passageways are twisting. When you plan your dive, consider the following points.

Usually penetrating a wreck is not necessary. It is much safer to explore the bustling marine life from outside.

Wreck penetration is likened to cave diving, so you should make preparations accordingly. It requires additional training and relevant qualifications, as well as laying guidelines, such as independent air source (additional alternate), two flashlights and a definite plan of exploration as well as exit points.

Aside from sea and ocean diving, there are freshwater ecosystems that offer much to both aspiring and experienced divers.

Fish are less likely to be afraid of you as they do not encounter divers on a daily basis, so river provides nice opportunities for drift diving. You can find a lot of fish in deep pools, as well as on bends. Lakes can provide more or less traditional yet excellent experience for divers.

What you might consider for freshwater diving beforehand

Other people

Do not neglect other water users like boaters or anglers as well as recreation people. Their activity might be heavier than usually in the sea.

Ownership

Many rivers and other freshwater systems are privately owned, so you need special permissions before you start diving.

Altitude

Sometimes special dive tables are required for rivers or lakes that are high above the sea level.

Freshwater diving requires some specific diving skills like:

Good buoyancy control

Refine your buoyancy control as it is more difficult to retain buoyancy in river freshwater than in ocean saltwater.

Controlled fin kicks

You should be very accurate as not to disturb the bottom as lake beds consist of fine substrate and require controlled fin kicks.

Both cave and ice diving are considered overhead environment diving. It means a lack of direct ascent to a surface. In these conditions diving becomes a special skill, and you should not underestimate the perils of this activity. Everything is essential for a safe dive including good logistical support, experience and appropriate training.

You will need extra equipment for ice diving such as double hood (two thick hoods) to protect your valuable head from the cold, specially modified cold-water regulator that is less susceptible to the extreme cold and dry-glove system that keeps your hands warm and functioning.

Thermal protection is very important, and conventional equipment is not enough at these extremely low temperatures. Ice diving involves diving beneath glaciers or through a hole in the ice. The environment is often strange and frightening.

Cave diving is considered elite sport, and it is really one of the extreme forms of scuba diving. A diver in a cave is often as much isolated from the world as an astronaut, so he should be brave and self-reliant. Cave diving requires a cool head and high level of commitment, as well as additional specialized gear such as navigational guidelines, complex gas mixtures, scooters and specialized light systems.