My first question would be how big do you want to go? Dumas has some decent scale boats that might work for you. A couple examples would be:
1) Dauntless Dumas Products Estore
2) USS Whitehall Dumas Products Estore
3) City of Buffalo Dumas Products Estore
4) Mt Washington Dumas Products Estore
5) If you want a tug, this should get you to several - Dumas Products Estore