Here are some tricks that help me (not that I'm greatly susceptible) and also almost everyone I've been able to persuade to try them.
Basically they're almost all aimed at reducing conflicting sources of information:
1) Either watch the horizon, or if below, close your eyes
(NB: the latter requires 2) and 3) in addition)
2) Immobilise your head
(eg find a corner to nestle it into)
3) Get your head
(and, for comfort, your body) horizontal
4) Do not go forward of the center of pitch
if the heading is upwind
5) If lying down, the floor may be better than a high bunk
6) As a preventive measure: when rough conditions are expected, eat dry, bland, bulky food
to partly fill and stabilise the stomach.
7a) SMILING can be a preventative, especially for brief periods eg moving from cockpit
to bunk, removing wet gear
7b) (this recommendation is for other people):
Unless this would be a breach of trust: Do not discuss safety
concerns within the hearing of badly affected sufferers:
If possible without compromising your integrity and reputation, present a cheerful front.
1) If you can see the horizon, the brain can make some sense of why you are experiencing accelerations, because it has a reference datum to measure the visible motions against. Steering
helps further because the person controlling the boat gains added information (and a useful external focus) from guiding the boat over the waves.
2) Because the head is an inverted pendulum; sensitive force transducers in the neck send lateral acceleration information to the brain. This reduced perceived
3) To disable the ear canal 'spirit level' angular sensors, and (by a different mechanism) the linear acceleration sensors (Google "otolith organs", again reducing perceived accelerations. It has been claimed it also "prevents histamine from reaching the brain, decreasing nausea".
The problem with lying down as a strategy is the time it takes to get below and get undressed. During this time, the 'sufferer' can become very ill indeed. To the extent possible, get undressed where you can see the horizon WELL.
In the cockpit
, if possible.
Unaffected crew should act as devoted slaves and body-servants to streamline the whole 'getting horizontal' mission, certainly not get in the friggin' way.
It's not just altruism: Their safety
, too, will end up on the table, if seasickness becomes prolonged and savage, to the point where it weakens the overall crew capability.
4) To reduce actual
5) To reduce actual sideways accelerations
6) Avoid spicy and fatty or highly sweetened or rich food
altogether. Avoid diuretic drinks. Hydrate judiciously (preferably with a mild electrolyte), little sips, often.
It's a matter of experimentation: There's a soft thick flaky white cracker biscuit in NZ with little flavour called a "Cornish Wafer" which seems to work for many people.
But couple of my friends eat Watties (unflavoured) rice pudding, straight from the tin, cold, in storms - in any other circumstance they reckon it would make them puke!
7a) It is reputed to suppress the gag reflex, and is supposed to work in other instances of nausea. I suspect it's at least as much a case of a 'fake it till you make it' strategy
7b) Even the toughest cookies are emotionally fragile when seriously seasick.
I once made friends for life of a couple of hard-bitten scientists, whose professional lives are spent in the subantarctic, who were 'dying' in their bunks when their 55 tonne chartered transport (a sailing vessel) was knocked flat in the deep and empty south, out of range of any rescue
On my way to the companionway
, I made a detour past their bunks and said something like "We apologise for this short interruption to our advertised schedule: normal progress will be resumed as soon as possible".
One of them, normally undemonstrative, immediately burst into tears, threw her arms around my neck and hugged me. I wonder if it tipped the balance for them, some sort of turning point, because they got back to NZ, their boss made a point of tracking me down and thanking me personally.
One theory about conflicting information is that the human brain cannot hold different versions of a model of reality: it has to pick winners, and it cannot do that if there are too many.
A subtheory is that the usual scenario in early protohuman times leading to serious conflicting information from various parts
of the body was 'sensory malfunction' arising from accidental poisoning from eating natural toxins. If so, vomiting would be a useful response.
Possibly those lucky few who are not "afflicted" might actually represent a *less* highly evolved slice of humanity?