Divers are often on boats and for many, this means seasickness. Seasickness, otherwise known as motion sickness, is caused when there is an over-stimulation of the semicircular canals of the inner ear. When there is also something called visual mismatching, which occurs when the signals from the vestibular, visual, and proprioceptive receptors are mismatched, it can bring on vertigo. Both visual mismatching and vertigo transmit messages to the brain that can cause nausea and vomiting. The vomiting reflex is brought about by a reaction between the central nervous system and the gastrointestinal system. Seasickness is downright uncomfortable for anyone and is especially concerning for divers because if it is not managed properly, it can ruin an otherwise enjoyable dive. Let's discuss the issue in more depth.
If a diver is known to suffer from seasickness, the condition must be treated to help avoid the uncomfortable symptoms that often accompany seasickness as well as the possible life-threatening situations which may arise if the condition is not properly treated. The threat of vomiting once geared up and in the water is something that simply should not be ignored. If a diver vomits while underwater, the vomit may get into the regulator and subsequently into the lungs which may lead to complications such as an infection in the lungs. If a diver experiences seasickness, then he or she should not dive unless it is controlled. Now, here is the hitch. Seasickness medications must be taken as a preventative measure. In other words, once an episode of seasickness has occurred, there is no going back. It is difficult to treat once it has begun and, as such, medications are often taken in advance of actually getting on the dive boat.
The medications used to treat seasickness are called anti-emetics. These drugs are either a form of anti-histamines (particularly the over-the-counter ones) or are structured very much like anti-histamines. The problem with taking these medications prior to diving is that they may have side effects that could cause issues during a dive. In the case of anti-emetics, there is a chance that these drugs will have a sedative effect on the diver because they can cross the blood-brain barrier. This can be very dangerous for the diver and the effects can be compounded if the diver is medicated for allergies and vertigo at the same time. Another option for divers and one that may be better in most cases is the scopolamine patch. This patch is available by prescription and it must be worn for a few hours before getting on the boat. There are potential side effects to this drug as well, including drowsiness and mental confusion, but are generally mild.
Fortunately, there are also non-drug alternative treatments for seasickness. The most popular of these are Seabands and Travelaides, both of which are specially designed bands that are worn on the arm three finger widths above the wrist. These bands have a plastic bubble that presses on the Neiguan point, an acupressure point that is on the inside of the arm. While there have been varying degrees of success using these methods, many people have found relief from the nausea that goes with seasickness, even after the nausea has started. This may be an option for divers to try if they wish to avoid taking seasickness medications prior to diving.
Divers who experience seasickness and want to dive must be prepared to take care of the seasickness before it starts. Careful consideration must be given to the potential side effects of the medications used to treat seasickness and if a diver experiences severe side effects, then he or she should refrain from diving. Divers can also experience a feeling of vertigo in the water, both on the descent and ascent, but this usually does not present a problem. If you are in doubt, the best thing to do is to consult your doctor to determine if it is safe for you to dive. After all, some of the best diving is done from a boat and you do not want seasickness to interfere with your big diving plans. At the same time, you also don't want to ruin your dive or put your life at risk either. So be smart and take the time to ensure your safety in the water so that you can truly enjoy your dive.