The light rain obscured my vision somewhat. It wasn't until the boat passed that I got its name as the Holy Angel.
From the photos, I could see that the windows on the lower deck were round, indicating that it spends some time near deep water. And I noticed that it had no corporate emblem on the smokestacks.
I looked it up later on Dick's Towboat Gallery and saw that it has had several names in the past 60 years.