Warning signs during a dive that mean you should end it

A dive should end when something is wrong with your equipment, your air, your body, or the water around you, even if the dive is only partly complete. Calling off a dive early is a normal part of diving, and the skill lies in recognizing the signal early and acting before the problem grows. Most of the warning signs below are easier to handle on the way up than in the middle of a struggle at depth.

The decision to end a dive should be made without guilt or debate. If you are unsure whether to continue, the safer option is almost always to start the ascent, signal your buddy, and talk on the surface. Agree on this with your buddy before entry, so either diver can call the dive without needing to justify it first.

Equipment that behaves unexpectedly

A mask that floods repeatedly, a regulator that free-flows or breathes hard, an inflator that sticks, a weight or harness that shifts, or a gauge that stops reading are all reasons to pause and assess. Some problems can be fixed quickly on the spot, such as clearing a mask or switching to an alternate air source. If the fix is not simple, or the problem returns, end the dive.

A free-flowing regulator needs quick action, because it wastes air and can make breathing difficult. Your buddy can offer an alternate air source while you move into the ascent. Equipment problems are not a failure of the dive. They are the reason you practice the buddy check and the skills in your training.

Current that is stronger than planned

Currents change, and a site that was calm during the briefing can become difficult within minutes. If you have to work hard to stay in place, feel yourself being pushed away from the planned route, or cannot make progress toward the exit, end the dive early. Do not fight a strong current for long, because that consumes air and energy quickly.

Use the planned exit and the route your instructor or guide described, and surface where it is safe to do so. If you lose contact with your buddy in current, follow the separation steps you agreed before the dive. Calling for help from the boat or shore is part of the plan, not a sign that you have done something wrong.

Low air and gas that runs short

When your gauge reaches the pressure at which you planned to begin your ascent, start the ascent, even if the dive could continue. The same applies if your buddy signals that they are out of air or running low. Share air calmly, keep the ascent controlled, and watch the gauge as you rise.

Low air is a warning that the plan has changed. If the gas is lower than expected, or air use is faster because of cold, stress, or effort, do not add time to the dive to make up for it. The reserve exists so that you can finish the dive safely even when the start did not go as planned.

Feeling unwell underwater

Cold that you cannot control, shivering that does not stop, stiff hands that make your gear hard to handle, dizziness, nausea, headache, shortness of breath, or unusual fatigue are reasons to end the dive. Cold deserves attention early, so end the dive while you can still manage your gear and your ascent. Do not try to push through symptoms. These signs can reflect a problem with the body, the gas, or the conditions, and they can get worse as the dive continues.

At depth, nitrogen narcosis can cause giddiness, confusion, poor judgment, or a sense of euphoria. Narcosis is a reason to ascend, not to continue. Tell your buddy what you feel, use the signals you agreed, and move to shallower water as part of a controlled ascent. Mention any unusual feeling to your instructor afterward, because it affects the next dive.

Getting help after you surface

Some symptoms appear after the dive rather than during it. Joint pain, numbness, tingling, weakness, dizziness, confusion, changes in vision, or difficulty breathing can indicate decompression illness or another injury, and they need prompt medical attention. Do not wait to see whether they go away. Ask the crew or another trained provider to give emergency oxygen if it is available, and call local emergency services or a diving emergency hotline. Tell the responders that you have been diving and when you last surfaced. Before you dive, find out where the nearest emergency service and any diving medicine facility are, so you are not searching for them in the middle of an emergency.

Until a doctor has evaluated you, avoid flying or traveling to altitude, since these can make some symptoms worse. Note the depth, time, gas used, and any problems that occurred during the dive, because this information helps medical staff. A calm, honest report is more useful than one that minimizes what happened.

Discuss these signs with your buddy before every dive, and agree that either person can end the dive at any time. Ending a dive early costs very little compared with continuing one that has gone wrong, and experienced divers are often the first to call a dive when something feels off.