Thanks for the tip on a sea-sickness pill.
My reliable Avomine stopped being sold many years ago. Not before it had helped me across a rough North Sea from Bergen to Newcastle in a large RORO*** vehicle ferry. Swaying down the passage to our cabin - it was noticed that small foil-lined cardboard boxes had been placed every few metres. My companion had laughed at my taking a pill on the relatively calm outward leg. Now she said sheepishly - "Can I have one of your pills?".
***Roll on, Roll off. Although where they provide extensive sleeping arrangements for passengers they are more likely termed ROPAX.