Is a merchant marine a reservist? if not, then can you still deduct MIE as a result of being in the transportation industry?

I'm a member of SIU (a mariners union affiliated with AFL-CIO),I travel for months at a time on a cargo/cable ship outside of the US.  Although it didn't;t occur in 2018, our ship can come under military contract. Can I still deduct the MIE per the Federal foreign rates?  I don't get a per diem from my employer and not reimbursed for expenses.