What is the correct action to take if a diver experiences symptoms of DCS?

When a diver experiences symptoms of decompression sickness (DCS), the most appropriate action is to begin a controlled ascent to the surface and seek medical attention. DCS occurs when nitrogen bubbles form in the body due to changes in pressure, typically from ascending too quickly after a dive. Symptoms can include joint pain, dizziness, fatigue, and other serious conditions.

Performing a controlled ascent mitigates the risk of worsening the situation, as a rapid ascent can increase the risk of additional gas bubbles forming and further complicate the diver's health. Controlled ascents follow safe diving practices by allowing for decompression stops if needed, which can help minimize the risks associated with DCS.

Once safely at the surface, immediate medical attention is crucial. Treatment for DCS often involves hyperbaric oxygen therapy, which is most effective when administered promptly after symptoms arise. Therefore, seeking medical help after an appropriate ascent is vital for the diver's recovery.

The other actions listed, such as ignoring symptoms or attempting to ascend rapidly, do not align with safe diving practices and can lead to further health complications.