What happens if you need to throw up underwater? The answer is that almost anything a person can do on the surface (cough, hiccup, hock a loogie, etc.) a diver can do underwater with a scuba regulator in his mouth. Regulators are equipped with exhaust valves (where the exhaled air bubbles out) and any almost substance exiting a diver's mouth can be blown out the exhaust valve along with the diver's exhaled air, including vomit. Here's what scuba divers need to know about vomiting underwater.

Is It Common to Have to Vomit Underwater?

No. In fact, if a diver is feeling seasick on a dive boat, the best thing he can do is to hop in the water. Once a diver is off the boat, his seasickness usually disappears because he is moving with the water instead of bouncing around on top if it. Entering the water also distances a diver from boat exhaust, which can exacerbate seasickness.

Underwater, a diver is most likely to experience seasickness near or on the surface, where the rocking motion of the waves or surge can be felt on rough days. Other causes of nausea can be vertigo from incomplete ear equalization or an upset stomach caused by exotic food at dive locations.

What Should You Do If You Must Vomit Underwater?

Do not remove your regulator. After vomiting, a person will reflexively gasp for air. If a diver removes his regulator to vomit, he may not be able to replace it in time and may inadvertently inhale water. Instead, a diver should hold his regulator in his mouth and vomit into the regulator mouthpiece. This will not contaminate his air supply – the vomit will exit through the one-way exhalation valve. The first breath after vomiting should be taken as carefully as possible, ensuring that any leftovers do not get inhaled.

Purge the regulator if needed. After vomiting, a diver can use the regulator's purge button to flood the regulator second stage with air and force any leftover debris out the exhaust valves. A diver purging the regulator after vomiting should take care to place his tongue over the regulator mouthpiece while pressing the purge button so that any remaining vomit does not get blown back into his mouth.

Be prepared to switch to the alternate air source. Depending upon a diver's last meal and chewing habits, vomit may be of different consistencies. If a diver is unlucky enough to have the chunky variety, pieces of puke could become lodged in the regulator mouthpiece and cause it to free-flow or malfunction. This is what alternate air source regulators are for! (They are also useful if breathing from a recently puked in regulator simply disgusts you). If a diver does switch to his alternate air source, he should end the dive because diving without an alternate air source regulator available for his buddy is unsafe.

End the dive if nausea continues. Sometimes vomiting makes you feel better – embarrassed and self-conscious, but better nonetheless. If vomiting once seems to alleviate nausea, a diver may feel confident in continuing his dive. However, if nausea does not abate, it is time to surface and end the dive.

Wash and service the regulator second stage. Depending on a diver's pride, the worst part of vomiting underwater may be admitting that it happened. However, a regulator that has been vomited into should be thoroughly sanitized and may require servicing if any debris remains. A diver who has vomited in his regulator must swallow his pride and alert the appropriate person (particularly if he is renting a regulator) to make sure that the regulator is cleaned and working properly.

Vomiting underwater is never fun, but it can be done safely when unavoidable. As most less-than-pleasant experiences in life, even vomiting underwater has a silver lining. Fish love diver puke. A diver who vomits underwater will quickly be surrounded by schools of fish eager to share his last meal. In fact, many experienced divers refer to vomiting underwater as “feeding the fish” for this very reason!