If a scuba diver suddenly experiences illness or a severe headache underwater, immediate and decisive action is required. The submerged environment amplifies the danger of physical symptoms, which can quickly impair judgment, motor skills, or the ability to manage life support equipment. Diving safety protocols dictate that any symptom at depth, such as a sudden headache or dizziness, must never be ignored. A practiced protocol must be implemented immediately to ensure the safety of the affected diver and their buddy. This response involves recognizing the problem, signaling for assistance, executing a controlled exit, and culminating in a specialized post-dive medical assessment.
Immediate Protocol for Recognizing and Signaling Distress
The moment a diver recognizes a problem, all movement and activity must cease immediately to conserve gas and regain composure. The first action is to signal the dive buddy using the universal “Problem/Not OK” hand signal, which is a flat hand rotated slowly from side to side. The affected diver should then point to the source of the problem, such as tapping their head for a headache or ear for equalization issues.
Upon receiving the distress signal, the buddy must acknowledge it immediately and assess the diver’s gauge readings, including air pressure and depth. The decision to abort the dive must be made instantly, regardless of the remaining bottom time or any planned decompression schedule. Maintaining neutral buoyancy control is paramount during this initial coordination phase to prevent an uncontrolled ascent or descent.
The pair must then coordinate their exit, ensuring that the affected diver remains in contact with their buddy throughout the procedure. This is the stage where the team transitions from problem recognition to the physical act of ascending. The primary goal is to move the diver toward the surface in the safest, most controlled manner possible.
Executing a Controlled Emergency Ascent
Once the decision is made to ascend, the steps must be executed with precision to mitigate the risk of decompression sickness (DCS) or lung overexpansion injury. The ascent rate must be strictly monitored and controlled. Most recreational training agencies recommend a rate no faster than 30 feet (9 meters) per minute, as a slow, continuous ascent minimizes decompression stress.
Throughout the ascent, both divers must continuously manage buoyancy by venting air from their buoyancy control device (BCD) or dry suit. This counteracts the expansion of air due to decreasing ambient pressure. The affected diver must also exhale continuously and never hold their breath, which prevents a life-threatening lung overexpansion injury. Equalization of the ears and sinuses should continue normally during the upward movement.
Even in an emergency, a safety stop should ideally be performed unless the diver’s condition requires immediate surface access for medical reasons. The standard safety stop involves pausing the ascent for three to five minutes at a depth between 15 and 20 feet (3 to 6 meters). This pause allows for off-gassing and significantly reduces the risk of DCS. The buddy must monitor the affected diver closely during this time.
Post-Dive Assessment and Emergency Response
Once safely on the surface, the immediate priority is to assess the diver’s symptoms. If a dive-related injury is suspected, 100% oxygen must be administered. High-concentration normobaric oxygen is the primary first-aid treatment for suspected Decompression Illness (DCI), which includes DCS and Arterial Gas Embolism (AGE). Administering oxygen increases the diffusion gradient, helping the body rapidly eliminate inert gas from the tissues and blood.
Symptoms of sudden illness underwater, such as severe headache, nausea, dizziness, or profound fatigue, are nonspecific and can indicate serious conditions. These possibilities include Decompression Sickness, Carbon Monoxide (CO) poisoning from contaminated breathing gas, or various forms of barotrauma, such as inner ear or sinus squeeze. Any unusual symptom occurring within 48 hours of a dive should be presumed to be DCI until proven otherwise.
The injured diver must be kept resting and warm, and emergency medical services (EMS) should be contacted immediately. It is recommended to contact a specialized resource like the Divers Alert Network (DAN) Emergency Hotline. These organizations provide expert consultation and coordinate appropriate care, including transport to a facility with a recompression chamber. Medical professionals specializing in diving medicine must make the final determination of the cause and treatment.