I was on the Infinity repositioning cruise last May from SF to Alaska. About 15 minutes after sailing under the golden gate bridge, we hit very rough water. I ended up having to leave the dinner table early and spent the next 24 hours in bed. I am not sure if this was an unusual occurance or was weather related. I am not prone to sea sickness, our waiter told us that out of 1800 people onboard they had 600 no shows for dinner.