My father, Robert Logan (now 88yo) was on Mobil Tankers in the 70s & 80s as an engineer officer.
Names of boats I can remember are Pinnacle, Pegasus, Transporter.
One of them was in dry dock in Holland in the mid 70s which I remember because I got to spend 3 months on the ship. I think I was about 10yo.
I'm sure he'd be interested to hear from anyone he sailed with.