I live in MD and have driven to Manhattan for a cruise. My recommendation is to leave very early (like 6 am if you want to be on the boat at 1 pm). Hopefully, the worst case is that you are there early and either on the boat early or hanging around. On a nominal case, leaving at 6 gets you to the tunnel towards the end of rush hour. Even if it took two hours to get through, you are still good. Listen to the traffic reports in case one Hudson River crossing is better than another.