If deep-sea divers ascend too rapidly from ocean depths, the decreasing pressure causes nitrogen to be released as gas bubbles in the blood  This condition is known as the bends
Sea snakes, who, like humans, breathe air that contributes nitrogen to the blood, are nevertheless able to make extremely rapid ascents and descents in ocean waters without suffering from the bends
Human deep-sea divers are trained to make several stops on ascending from deep water in order to adjust to decreasing pressure gradually, whereas sea snakes ascend from ocean depths without stopping.