Marine mammals, as a general rule, do not breathe air under pressure, making the likelihood of experiencing Decompression Sickness (DCI) extremely rare. In contrast, humans can be susceptible to DCI due to the nature of SCUBA diving, where compressed gases like air are breathed. For human divers, the speed of descent or ascent plays a crucial role in the occurrence of DCI.

While marine mammals have their own unique adaptations and mechanisms to mitigate the effects of pressure changes during dives, human divers face the risk of DCI due to the compressed gas they breathe underwater. It is essential for human divers to carefully manage their ascent and descent rates to minimize the potential for DCI.

The contrast in breathing mechanisms and gas composition between marine mammals and human divers underscores the differences in how DCI can affect these two groups.