I have only been on two ocean cruises and had it both times. After first cruise it was severe and I had an infusion which stopped it (antiemetic). Just home from a two week Alaska cruise and I had it during (port stops) and afterwards. I took prescribed Metoclopramide (Maxalon) and this helped and it stopped completely after 3-4 days.
FWIW I’ve also had BPPV (Vertigo) and they feel completely different.