Last time I put on my scuba gear with the intention of diving in Devon, one of my co-divers started to feel very ill soon after we set out in our little inflatable. He was down from London and he became quite distressed as we skimmed across the waves in Plymouth Sound. We had to stop a couple of times and put him into the water to recover before we reached our intended dive site. He must have been one of those individuals who is intensely sensitive to motion – or rather, uninterpretable motion. It is unfamiliar movement that is most likely to upset people; the problem is not so much with the motion itself but with the body’s inability to predict it. My friend just didn’t know when we were going to hit a wave or which way the boat would lurch next.
Anyone will get motion sickness if the conditions are bad enough, but it’s particularly common in boats. A survey of British ferries found that 21% of passengers felt ill and 7% actually vomited, whereas the motion sickness hit-rate in large passenger airlines – which usually fly above the worst turbulence – is less than 1%. Motion sickness is common in all boats – big and small – and it is more likely if the boat you are in is moving fast, cornering sharply and lurching or bouncing off wave tops.
The problem comes when the eyes give the brain one set of information while the balance organs in the inner ear tell the brain something rather different. Focusing up-close – at the bottom of the boat, for example – will make things worse. Looking at the horizon should help, as does lying flat with your eyes closed – although my friend who was wearing his air tanks couldn’t manage this in our cramped little inflatable. Motion sickness is a peculiar phenomenon; there are even some people who are so sensitive that they feel ill being wheeled along a hospital corridor on a trolley. Virtual journeys, such as those experienced in flight simulators or even cinemas, can also make people seasick.
Children suffer more commonly than adults but seasickness is rare below the age of two; the peak rate is between the ages of about three and 12. Women are almost twice as susceptible as men. Most people (95%) will get their ‘sea legs’ on the second or third day of travelling on a ship or boat so their motion sickness settles.
In the usual order of onset, are:
> loss of appetite;
> an awareness of the stomach;
> yawning;
> loss of colour;
> feeling of apathy and illness;
> cold sweats;
> increased salivation;
> nausea;
> vomiting;
> dry retching;
> dehydration, headache and dizziness;
> absolute misery.
Those who suffer need to eat a minimal, bland, easily digestible diet to avoid getting that slopping feeling in the stomach. Fizzy drinks and greasy, heavy food should be avoided. It would also be wise to find a remedy to take on your travels, but it is important to be aware that if the motion stimulus is too great, or if treatment is taken too late, nothing is likely to work, except sometimes an injection. Ginger is a useful cure and can be taken in the form of biscuits. An effective dose is one gram of ginger extract, which is equivalent to a handful of fresh root ginger. Sea bands that press on acupuncture points are successful with some people but not others; the RAF did some research on them and concluded that they were not effective enough for its stringent needs.
However, seasickness has a strong psychological element and faith in a remedy will make the treatment work in many instances – especially where children are involved. This becomes clear when you think what it is like to be on board a ship that is pitching and rolling, and when people are chucking up all around you. Most would feel nauseated in such circumstances – even if they usually have a robust constitution.
There are two groups of medicines that are very useful in controlling motion sickness (not all remedies for nausea and vomiting work well for this specific ailment). The most effective are preparations containing hyoscine (which is also called scopolamine) and these come in chewable or melt-in-the-mouth preparations (eg Kwells, Joy-Rides); they begin acting within about 30 minutes – very rapid for a tablet. The effect lasts for about four hours and can help the symptoms somewhat even after the sickness has started.
The disadvantages of taking hyoscine are that the effect wears off too soon for longer journeys, and taking a second dose usually causes an unacceptable level of side-effects, especially sedation or drowsiness, a dry mouth and sometimes blurred vision. However, because these start working the quickest, hyoscine-based preparations are great if you are unsure whether you are going to be ill or not. Hyoscine also comes as a slow-release patch (Scopoderm, Transderm Scop); these control symptoms for 72 hours and have fewer side-effects than tablets but, in Britain, they have to be prescribed by a doctor.
For those who just know that they are going to puke when they get afloat, or for people who will be voyaging for more than four hours, the best preparations to take are in the antihistamine group of medicines. Cinnarizine (marketed as Stugeron) is my favourite but meclozine (Sea-Legs) is also good, and both work quite well and cause few side-effects.
These antihistamines do need to be taken well before they are needed, though. The Stugeron packet suggests dosing only two hours before travel. However, the preparation is best taken four hours before or, if you are leaving early in the morning, the night before; a second, top-up dose can then be taken the following morning. Further doses need to be repeated every eight hours if the voyage demands. I would choose one of these non-sedating antihistamine preparations if I needed to prevent sea sickness on the way to a scuba dive since the alternative, hyoscine, may sedate – an undesirable side effect that might render submarine decision-making more difficult.
> Minimise head movement.
> Lie down.
> If inside a cabin, close your eyes if possible.
> If on deck, look at the horizon.
> On big vessels choose a cabin on a middle deck, amidships.
> Don’t try to read a book or navigate.
> Try to distract your mind from the symptoms by looking for birds or other boats.
> Take only small portions of easily digestible, bland food.
> Avoid fatty foods.
> Avoid fizzy drinks.
> If you feel like eating, take high carbohydrate foods like biscuits, crackers, pasta or rice.
> Choose something that won’t taste too bad on regurgitation – like a jam sandwich.
> Nibble on ginger biscuits.
> Carry some light snacks on your voyage so that you don’t feel you have to eat any heavy meals that are provided.
> Take in lots of fresh air.
One of the most likely places to experience seasickness (even for those who seldom suffer) is the Antarctic, where conditions are often very rough indeed. If you’re embarking on any trip where the journey is likely to be rough, especially voyages on open sea, make sure you pack some pills or visit your doctor for the patch.
Dr Jane Wilson-Howarth is a GP and author of 'Bugs, Bites & Bowels' (Cadogan), 'Shitting Pretty' (Traveler’s Tales), 'Your Child’s Health Abroad' (Bradt) and 'Lemurs of the Lost World' (Impact Books). She has two very pukey children who have taught her a great deal about curing motion sickness.
