If there's a problem with the air tank, the diver could end up stuck too far underwater to be able to get up in time to breathe.
要是氧气筒出了问题，潜水员最后可能会受困在过深的水底而无法及时浮上水面呼吸。Police divers were carrying out a search of the river as an investigation was launched by the Federal Aviation Administration.
联邦航空管理局（FederalAviationAdministration）已展开了调查，并派出警察潜水员对水下进行搜索。However huge the arm, it was fragile, and divers filled a balloon with air from a scuba mouthpiece to gently raise it to the surface.
这个胳膊体形巨大，但易碎。潜水员用自携式水下呼吸器把气球充满气，让它缓缓地把胳膊带到水面。Olympic athletes and divers can hold their breath for minutes at a time while heavy smokers gasp for air after just a few seconds .
奥运会运动员和潜水员一个可以憋气几分钟，而吸烟很多的人只能憋几分钟就得去喘气。The deep-sea diver had scarcely reached the bottom when a message came from the surface which left him in a dilemma.
深海潜水员刚小心翼翼地到达海底，水面上传来的一条消息让他进退两难。But when divers moved into the mine early on Friday the body of the first miner was discovered at the bottom of the main shaft.
但是当潜水员在周五早些时候向矿井靠近的时候，第一具尸体是在坑道的底部发现的。The condition, known as pulmonary barotrauma , resembles the injuries SCUBA divers suffer if they return to the surface too quickly.
这种情况被称为“肺气压伤”，类似于身背水肺的潜水员返回表面太快时所遭受的伤害。At the heart of any submersible lies the hollow sphere where the aquanauts work.
潜水器的核心是用于潜水员工作的空心球舱。Often a diver must grope his way through icy water filled with mud and silt that make it hard see.
潜水员常常要在充满泥浆和淤泥，因而能见度极差的冰冷的水中摸索前行。