Bobby West sits on his porch overlooking the Horn Harbor lot he has lived on his whole life, with his son Robby next to him. They’ll soon trade their navy-blue Vane Brothers polo shirts for coveralls, but for now they are business casual.

“And there’s Wesley,” Robby says of his son as a blue pickup pulls in. “He’ll sit in there and text a while, I’m sure.”

The three generations of Wests make up the heart of the crew of the Tug Jacksonville, a 100-foot articulated tugboat owned and operated by Vane Brothers, a company that moves petroleum products by water on both coasts.

In the background on the porch is a portrait of an older man in a captain’s hat—Bobby’s late father William Clyde West. William Clyde, like his father before him and the three generations in front of him, worked the water, first as watermen and then on tugboats.

“I used to watch him go up and down the bay and think ‘What a boring job,&rsq...