I honestly have no idea, but I think his customers are mostly moving goods up and down the Mississippi River. So there's probably some specific needs there.
There's tons of "small money" (read, too small for a VC, quite comfortable for a single developer or small company) to be made helping to automate small businesses, especially things that are built on a lot of independent contractors.
Some VC firm tried to do it for trucking and exploded recently, but there's still needs there that can be filled.
The key is to fill slowly and grow; for an example (and completely guessing) you could have an app that starts out as just a "tugboat parking availability" or whatever, and then you find what the users using it would also like to see.
