Then somehow… You fell through the cracks at NMC. I have never heard of this (unless you have not disclosed the actual path you have taken). The path to upgrade an existing OUTV to the Master of Towing Vessels endorsement on a license was ended around 2002. The people who had a OUTV had a deadline to have the licenses changed over to the new license program. There have been several people over the years on Gcaptain who have complained of this exact same issue, and were ‘left out in the cold’ because they didn’t meet the deadline’. So, I would say either you were ‘exceptionally lucky’ or you are being unclear on your license progression. The term “Grandfather” as it applies to an original holder of an OUTV has been extinct since the final license renewals subsequent to the 2002 deadline. This would mean someone who renewed late would have been ‘done’ by 2007. I may be off by a year or so, but, the time has been up for several years. If you did an ‘apprentice mate’ license program then you were not grandfathered, but simply had to meet the new requirements.
I read one license (of an original grandfathered towing license from the early 70’s) that read: Licensed to serve as Master of Vessels (restricted to towing vessels less than 200 tons) Also, Master of Towing Vessels. Since this guy had never actually passed an exam, his license was specifically NOT grandfathered to a 200 ton Masters license. It was restricted to towing vessels only. Other people who have gotten a towing license have two distinct licenses. The first is a Master (or Mate) license, and a second Master (Mate) of Towing Vessels (MOTV) endorsement.