I worked on tugboats in NYH (149grt) for 202 days while holding 3/m unlimited oceans. Then decide to sail on my 3/m license deep sea. Does any of that tugboat time count towards 2/m
Yes.
From the USCG 2/M Upgrade checklist:
"360 days of service while holding an endorsement as 3rd Mate, OF WHICH
- 180 days of service as officer in charge of a navigational watch on
Ocean/NC steam or motor vessels, AND - Service as AB, Boatswain, or Quartermaster while holding an AB
endorsement accepted on a 2 for 1 basis for a maximum of 180 days"
Sounds like that 202 days of AB time will count as 101 days of time towards the upgrade.