Tonnage for 3rd mate assessments

I can not find anywhere in policy letter 01-02 what the vessel tonnage needs to be for the assessments for 500/1600/3rdmate unlimited.

As all the classes and assessments, are the same, just the sea time is different for all three license, does it matter what the vessel tonnage is??

My understanding is that it doesn’t matter, as long as it is on a vessel greater than 200 GRT. I know of several folks that have upgraded to 3M while serving on vessels less than 1600GRT or 3000ITC. What I’m not clear on is if the new STCW changes have any affect on this.