LT in the navy is the same as a CAPT in the other services. Still an O-3.
...Except the Navy and Air Force are the only services with CAPT as the abbreviation for Captain.
Navy CAPT = O-6 (= Army, Marine, Air Force Colonel (COL))
Air Force CAPT = O-3 (= Army, Marine CPT or Navy LT)
Cash is a Lt Commander