Great Lakes vs Mississippi Usefullness

[swaghauler]

They have a fairly robust assortment of Coast Guard ships that are specially designed for use on the Great lakes. They include...

USCGC Alder 225ft Multipurpose Cutter.
USCGC Buckthorn 100ft Buoy Tender
USCGC Bramble 180ft WWII Buoy Tender
USCGC Mackinaw 240ft Heavy Icebreaker/Cutter

and no less than six 140ft Icebreaking Tugs:
USCGC Biscayne Bay
USCGC Bristol Bay
USCGC Katmai Bay
USCGC Mobile Bay
USCGC Morrow Bay
USCGC Neah Bay

Combined with the two dozen lake freighters (mostly bulk haulers), there is a lot of available shipping on the Great Lakes.