Seasickness affects many people to varying degrees - even sailors with years of experience. Looking on the bright side, the body adapts after time. Fortunately, several remedies can be taken before setting sail. Pills can be obtained over the counter which help most people by sedating the balancing organs. The pills can cause drowsiness and should be taken with care.
Some people find special wrist bands effective.
There are also stick-on patches that can be worn on the skin behind the ear, but these are obtained by doctor's prescription only. You can often avoid seasickness by staying busy and keeping your mind occupied by taking over the helm or any other activity that will keep you above decks. Look at the distant horizon rather than the water close at hand. Take deep breaths and drink plenty of water. The worst thing that a person can do is go below decks with no land or horizon to look at.