Noticed they will swim with and along side of regular ships especially the shrimp boats lol but they never see. To swim next to tow boats. I mean they'll come around where we're not moving or they swim but us in the channel but that's a out it. Anyone might know why ? Figure it might be due to the way we make a wake ?

Probably dont get free food off the barges like they do off the other boats

As I understand it, they like to "Surf" the bow pressure wave of a pointy V bowed ship, and a barge bow is broad and flat.

^^^^^
This

Guessing this as well. Used to have groups of dolphins performing up near and alongside the bow of my destroyers (many years ago), V bow, etc....

Barge hulls displace water very differently, likely no attraction. Barges typically don't move very fast either.

Too slow.

This is my guess
Ever seen a dog chase a turtle for the fun of it

A barge has little wake and they love playing in wakes.

All the dolphins I saw throughout the Pacific, Sea of Japan, etc, all played around the bow. Too much turbulence off the fantail.

They're fun to chase in a kayak.