Gulf to Great Lakes
Check on the great circle route but I think you go through Chicago and follow the Illinois river south to the Ohio river. Then to the Tennessee river and follow it south on Kentucky lake. At Pickwick lake you get on the Tenn-Tom waterway to Mobile. From Mobile you can head straight across the Gulf to the Yucatan Pennisula and on to Panama. The other part of the great circle is going around Florida and up the east coast to the St Lawerence and then back to the Great lakes. For almost the entire route you have protected waterways. You can also go up the Hudson and the erie canal which would probably be safer. There is a website.