Well, maybe for the seasickness part because that definitely WORKED. No small matter because a cruise can be ruined by seasickness. In my case, I only experienced some ear popping but NO nausea.
Ginger ameliorates all kinds of nausea. That is why hospitals often provide patients with ginger ale after surgery involving anesthesia.
Ginger tea is also great for alleviating minor stomach upsets.
But I doubt that ginger can counteract blood alcohol levels. It might just make you feel a little less queasy.