Freediving

Freediving is diving underwater (usually in the ocean) without using a breathing apparatus (air carried in tanks on their backs or supplied through a hose). Free divers practice holding their breath for long periods of time so that they can stay underwater longer.
Usually free divers stay underwater for about 45 seconds. That allows them to explore about 30 feet underwater. Some freedivers can dive to over 100 metres (300 feet), and hold their breath for four minutes or longer.
In Greek, “Apnea” means “Without air” and free-diving is called “Apnea”. Free-diving is similar to snorkeling, but divers need to hold their breath if they go in deep water. Free-diving doesn't need tools for breathing. Free-divers hold their breath until going up to the surface of the sea instead of using an air tank. Therefore, the most important part of free-diving is learning to breathe well. Most people can free-dive since it doesn’t need a snorkel or scuba tank. However, free-divers condition their mind and body before going free-diving.
History.
Pile of shells around dwellings of the Stone Age prove that people caught food under the water. Free-diving started by getting food or trading items, but it has developed as leisure, with divers taking photos today. Today, free-diving is widely practiced as a leisure sport like snorkeling and spearfishing. Anyone can go to the sea and see all kinds of sea animals. Also, free-divers can feel peaceful in the water. Free-diving has grown in the past 10 years by many people want to be with nature.
Practice.
Learning to breathe is the most important part of free-diving practice. The way of staying in the water longer is to practice breathing slow and deep. Divers breathe in for 5 seconds and breathe out for 10-15 seconds. To avoid over-breathing, they breathe out for a long time more than breathing in. Free-divers practice how to breath in the water, and they can start free-diving when they have a pulse under 80/bpm.
Risks.
Free diving to great depth is especially dangerous, but any diver who is not well trained can panic, or otherwise fail to return to the surface before they use up the oxygen in their body. They can lose consciousness from anoxia and drown. Professional free-divers can go in the water over 400 feet without any tools for breathing. But some free-divers die. On November. 17, 2013, Nick Mevoli blacked out after trying free-diving at a Bahamas competition. He never woke up again.
Free-diving Tools.
Unlike scuba-diving, free-diving needs several basic tools for seeing, breathing, and moving well in the water. Free diving equipment includes a mask, snorkel, fins, wetsuit and weightbelt. Free-diving tools help free-divers to experience more in the water.
1) Mask.
Free-divers choose a lightweight mask to fit their faces to swim comfortably in the water. 
2) Snorkel.
Another important tool is a snorkel which helps free-divers breathe when swimming close to the surface of the water. It is good to choose a flexible snorkel to avoid biting too hard and to focus on relaxing.
3) Fins.
In addition, free-divers need a good fin for swimming better with small effort. Fins help free-divers to reduce using their energy and the heart rate. It helps to travel farther too.