My first ship back in the early 60's she had a Texaco funnel (wrong it was Caltex) while I was with her although all officers were Denholmes and it looks like that she has that in the pic.
I see that a lot of the comments are about size but in her day early 60's she was quite large interesting time.
I think it was the Texaco funnel marking PA but cannot be sure. The pic was taken in early 1972 and the San Fransisco run was the first depature from a long term charter from the Gulf to Sriracha(Thailand).
You're probably right Dave. I know that the Texaco funnels at the time had a broad green band with black top and bottom. It could well be the Naess funnel in this pic - unfortunately the grey matter won't go back far enough for detail.