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Seasickness Prevention and Treatment

Some of the world’s best dive sites are accessible only by boat, and unfortunately seasickness prevents some scuba divers from visiting their dream destinations. Unmanaged seasickness will make any boat trip miserable, and if relief cannot be found the effects can pose a serious threat to a diver’s health. Though there isn’t a cure for seasickness, there are ways to prevent it and manage it.

The word seasickness is a bit of a misnomer because motion, not water, is what causes affected individuals to feel ill. In fact, many divers who feel dizzy or nauseated on a dive boat discover the symptoms of their motion sickness disappear as soon as they get in the water (or descend). Motion sickness can occur when traveling on a boat, flying in an airplane or riding in a car. The repeated motions associated with these modes of transportation can disturb the motion-sensing organs in our inner ears, and motion sickness develop when the brain receives conflicting signals from different sensory organs.

If a boat passenger inside a windowless cabin can feel the boat moving up and down in their muscles and joints, their inner ears are telling them to balance according to this perceived motion and their eyes see surroundings that appear to be stationary, this passenger may start experiencing dizziness, nausea and vomiting. Scientists are still unsure why vomiting is one of the body’s reactions to these conflicting signals, but some hypothesize the body is reacting as if it has been poisoned and is attempting to purge toxins.

Given the right combination of motion stimuli and exposure time, anyone can experience motion sickness, but certain people are more susceptible. Women, children and those who suffer from migraine headaches are more likely to experience motion sickness.

Seasickness Prevention

Preventing seasickness is easier than treating it. Dehydration due to vomiting is a serious threat to divers who are prone to motion sickness, so if you are prone to it, take preventative measures before you feel unwell.

  • Do Your Homework – Choose the largest boat possible (opt for a catamaran if available). In general, the wider the beam, the more stable a boat will be. Avoid single-hulled sail boats and choose dive sites relatively close to shore.
  • The Day Before – Avoid drinking alcohol and eating heavy meals. Take antiemetic medication; some divers find taking Bonine or Dramamine the night before a dive to be more effective than taking it the morning of. Check the medication’s guidelines to see how long it takes to take effect and how long it lasts. Don’t dive under the influence of any medication you’re using for the first time.
  • The Day Of – Hydration is key, so drink plenty of water. Eat a light meal 45-60 minutes before boarding; an empty stomach is more susceptible to irritation.
  • Gear Up Right Away – Once onboard, assemble your dive gear on the dock or before the boat gets underway. In addition to making equipment set-up easier, this prevents you from having to look down while moving through swells.
  • Watch the Horizon – When possible, stare at an unmoving object in the distance, such as the horizon. Avoid reading, writing or using a mobile device for long periods.
  • Find a Stable Spot – Stand in the center of the boat, avoiding upper or lower decks where bobbing and swaying will be more pronounced.
  • Avoid Odours – Position yourself in a well-ventilated area. Stay away from strong smells such as cigarette smoke, perfume and engine exhaust.
  • Eat a Little, Stay Hydrated – Opt for easily-digestible snacks such as dry crackers or bread throughout the day. Stay hydrated with water or sports drinks; avoid carbonated drinks and caffeine.

Treatment

Over-the-Counter Medications


Anti-nausea medications such as Bonine (meclizine), Dramamine Less-Drowsy (meclizine), Dramamine (dimenhydrinate), Marezine (cyclizine), and Benadryl (diphenhydramine) work by suppressing nerve pathways between the control center in the brain that induces vomiting and other control centers. Drowsiness is a side effect of many of these medications, so experiment with them to test your susceptibility to drowsiness before using one of these medications while diving.

The Seasickness Patch

Some divers acquire a prescription for the scopolamine patch, which reduces nerve activity in the inner ear to prevent motion sickness. The patch releases the drug slowly through the skin; because scopolamine affects the central nervous system, its side effects can impair your ability to dive safely.

The most common side effects of scopolamine are dry mouth and blurred vision. Other side effects, more common in children and the elderly, include hallucinations, confusion, agitation and disorientation. Scopolamine can also cause problems for individuals with glaucoma or an enlarged prostate. Wearing a scopolamine patch for more than three days can bring on withdrawal symptoms that mimic symptoms of decompression sickness which can complicate proper diagnosis. If divers who wear the patch experience dizziness, nausea or vomiting within 24 hours of a dive, they should contact a physician.

Natural Seasickness Remedies

  • Ginger – For some individuals, consuming ginger tea, ginger candy or ginger ale can soothe the stomach. Research suggests ginger reduces contractions in the stomach, which may help relieve nausea.
  • Dive In – If you start to feel ill, ask if you can be one of the first to enter the water. Once submerged, the body no longer receives conflicting signals from the eyes and limbs, which can alleviate nausea. Make a shallow dive and conserve air so you can remain underwater as long as safely possible. If you become ill underwater, keep your primary regulator in your mouth and vomit through it. Most regulators can process vomit without issue, but it’s good to keep your spare second stage handy in case things get messy.
  • Acupressure Bands – According to traditional Chinese medicine, applying pressure to a point on the wrist known as “P6” can suppress nausea caused by motion sickness. The ReliefBand sends out a small electrical pulse; other bands simply apply pressure.

Before taking any medication or trying a natural remedy in a diving setting, know how it affects you. On a day when you won’t need to drive, operate heavy machinery or generally need your wits about you, take one dose and assess your condition. If you are unimpaired and pleased with the results, employ this method of seasickness prevention and book your next boat dive.

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