What are the first steps to take if a diver is suspected of having decompression illness?

Providing emergency oxygen and contacting emergency medical services (EMS) is a critical first response when a diver is suspected of having decompression illness. This situation requires immediate attention, as administering oxygen can help alleviate symptoms and prevent further complications. Oxygen is the primary treatment for decompression sickness, as it reduces nitrogen bubbles' size and helps remove them from the bloodstream, thereby aiding in the diver's recovery.

Contacting EMS is also vital, as further medical assistance will likely be required for definitive treatment at a hyperbaric facility. Prompt and appropriate responses can significantly influence the outcome for the affected diver.

In contrast, while assessing the diver's level of responsiveness is important for overall situational awareness and determining the appropriate course of action, it does not directly address the life-threatening condition of decompression illness. Additionally, administering a surface first aid kit may not specifically target the needs of a suspected decompression issue, and changing the dive location is irrelevant if the diver requires immediate medical intervention and oxygen therapy. Thus, the first steps should focus on providing emergency oxygen and contacting EMS for further assistance.