Upgrade Question:Third Mate to Second Mate

If I were to work on a vessel of 2200 GRT as a mate will i be able to use all 270 sea days (12 hour days) or 360 sea days (8 hour days) to upgrade to a Second Mate Unlimited?

If the time was while holding a third mate license then why wouldn’t it count?

here is the checklist:

http://www.uscg.mil/nmc/checklists/MCP-FM-NMC5-17%202nd%20Mate%20AGT.pdf?list1=checklists%2FMCP-FM-NMC5-17+2nd+Mate+AGT.pdf&B1=GO!

If you are worried about it being an OSV, don’t. You should be able to upgrade no problem. Have fun.