Since this is not a military expedition, the ship ranks don't necessarily match with people's Navy ranks.
This is purely OOC knowledge, save for Jake and Matt's characters, who would've been informed of their positions beforehand.
Chain of command is as follows:
Captain Avery Crane
Lieutenant Jackson Hazard
Sergeant Jordan Macree
Harlan Lincoln (formerly Corporal)
Dr. Cotton Parr
You'll notice Eli Carter missing from this particular roster. Where he falls is completely unknown to anyone.
Since this is NOT a GAF excursion, those in the military can decide just how ingrained their training is and how they'll be handling a mission not backed or enforced by the armed forces. Just another little dramatic titty-twist for you folks.