David James Elliott Lt., Lt. Cmdr. Harmon "Harm" Rabb, Jr. Actor, Director Catherine Bell Maj., Lt. Col. Sarah "Mac" MacKenzie Actor Patrick Laborteaux Lt. j.g., Lt. Bud Roberts Actor Karri Turner Ensign, Lt. j.g. Harriet Sims Actor Scott Lawrence Cmdr. Sturgis Turner Actor Zoe McLellan Petty Officer Jennifer Coates Actor David Andrews Maj. Gen. Gordon "Biff" Cresswell Actor Maria del Mar Guest Star John DeMita Guest Star Danneel Ackles Guest Star Jeff MacKay Guest Star Jordana Spiro Guest Star Mel Harris Guest Star Hallee Hirsh Guest Star Dey Young Guest Star Michael Bellisario Guest Star John Walcutt Guest Star Meta Golding Guest Star Chris Beetem Lt. Gregory Vukovic Actor Charles Floyd Johnson Guest Star, Executive Producer Donald P. Bellisario Executive Producer Stephen Zito Executive Producer, Writer Mark Horowitz Executive Producer Bradford May Director Kenneth Johnson Director Paul Levine Writer Oz Scott Director Dennis Smith Director Terrence O'Hara Director Jeannot Szwarc Director Michael Vejar Director Darcy Meyers Writer Larry Moskowitz Writer Don McGill Writer Vern Gillum Director Dana Coen Writer Philip DeGuere Jr. Writer