Scuba diving is a mode of underwater diving where the diver uses a self-contained underwater breathing apparatus (scuba) which is completely independent of surface supply, to breathe underwater.Scuba divers carry their own source of breathing gas, usually compressed air, allowing them greater independence and freedom of movement than surface-supplied divers, and longer underwater endurance than breath-hold divers. Open circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver through a regulator.

They may include additional cylinders for range extension, decompression gas or emergency breathing gas. Closed-circuit or semi-closed circuit rebreather scuba systems allow recycling of exhaled gases. The volume of gas used is reduced compared to that of open circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open circuit for the same gas consumption; they produce fewer bubbles and less noise than open circuit scuba which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.

12 Days - 11 Nights

The Tiananmen, a gate in the wall of the Imperial City, was built in 1415 during the Ming dynasty. In...

9 Days - 8 Nights

The Tiananmen, a gate in the wall of the Imperial City, was built in 1415 during the Ming dynasty. In...

8 Days - 7 Nights

2022年出发日期: 每周三(05/04-10/05); 每周三五(06/15-0/12) 保证停留黄石公园15大景点!! 3天2晚黄石公园,保证15大景点! 免费升级黄石景区木屋酒店,赏日出日落,景区木屋酒店! 入住黄石公园内,保证在最佳时间看最美的黄石! (仅限周三) 洛杉矶、拉斯维加斯、盐湖城任意进出,丰俭由人!

en_USEnglish