What is the maximum duration for continuing 100% oxygen after surfacing?

The maximum duration for continuing 100% oxygen after surfacing is established to mitigate the risks associated with decompression sickness. Following a dive, particularly one that involves deeper depths or longer durations, the body has absorbed nitrogen from the breathing mixture. Breathing 100% oxygen post-dive facilitates the elimination of this nitrogen from the body more efficiently.

The recommended duration of 3 hours allows for substantial decompression to occur, reducing the likelihood of nitrogen bubbles forming in the bloodstream or tissues, which can result in decompression sickness. This controlled oxygen exposure also aids in managing the effects of inert gas loading.

In contrast, shorter durations might not adequately promote safe off-gassing of nitrogen, while excessively long durations without proper indication can lead to oxygen toxicity. This balance is critical for diver safety and outlines the guideline of 3 hours for the maximum time to continue administering 100% oxygen.