Thanks Craig, I guess that's kinda sorta what I said?
I did a little reading this morning and you are correct. What struck me as strange is that you can spend one day on a vessel over 5 tons and get a 50T Master. This is based on meeting the other requirements for sea time of course. Got this when I Googled...
A USCG license as Master 100 ton issues the full authority of the OUPV
license plus the additional authority to operate any inspected vessel within
the tonnage limitations of the license. These licenses are issued as Master
25 ton, Master 50 ton or Master 100 ton, depending on the size of
vessels the qualifying sea service experience was on.
If all your qualifying experience was on vessels of less than 5 gross tons
you will receive a Master 25 ton license. If you have any sea service
experience on vessels over 5 gross tons you will receive a Master 50 ton
license. Licenses from 50 to 100 tons are issued in 50 ton increments,
rounded up, based on the following formula:
Either the maximum tonnage that 25% of the qualifying experience
was on OR 150% of the maximum tonnage that 50% of the
qualifying experience was on.