David James Elliott
as Captain Harmon "Harm" Rabb Jr., USN
Patrick Labyorteaux
as Captain Bud J. Roberts Jr., USN
Catherine Bell
as Lieutenant Colonel Sarah "Mac" MacKenzie, USMC
John M. Jackson
as Rear Admiral A.J. Chegwidden, USN
Karri Turner
as Lieutenant Harriet Sims-Roberts, USN
Chuck Carrington
as Yeoman First Class (YN1) Jason Tiner, USN
Trevor Goddard
as Lieutenant Commander Mic Brumby, CSC, RAN
Randy Vasquez
as Gunnery Sergeant Victor Galindez, USMC
Nanci Chambers
as Lieutenant Loren Singer, USN
Steven Culp
as Special Agent Clayton Webb
Scott Lawrence
as Commander Peter Ulysses "Sturgis" Turner, USN
Tracey Needham
as Lieutenant, Junior Grade Megan "Meg" Austin, USN
Zoe McLellan
as Legalman First Class (LN1) Jennifer "Jen" Coates, USN
Michael Bellisario
as Midshipman Third Class Michael "Mikey" Roberts, USNA
Terry O'Quinn
as Rear Admiral Thomas "CAG" Boone, USN
David Andrews
as Major General Gordon "Biff" Cresswell, USMC
Andrea Parker
as Commander Caitlin "Kate" Pike, USN
Chris Beetem
as Lieutenant Gregory Vukovic, USN