Sea turtles can hold their breath for varying lengths of time depending on their activity level. During routine activity, they typically hold their breath for about 4 to 7 minutes while diving. However, when resting or sleeping underwater, they can remain submerged for much longer periods, typically between 4 to 7 hours. In cold water during winter, when they enter a hibernation-like state with very little movement, they can hold their breath for up to 7 hours or even longer

. This remarkable ability is due to physiological adaptations such as a significantly reduced metabolic rate while resting, a slowed heart rate to conserve oxygen, and a high oxygen-carrying capacity in their blood. Additionally, during hibernation, they can use cloacal respiration, a process that allows some oxygen exchange through their cloaca, enabling them to survive submerged for extended periods

. In contrast, when sea turtles are active, such as foraging or escaping predators, they need to surface more frequently, usually every few minutes, because they consume oxygen faster