Used to live in Navarre Beach in the '90s. At that time, Hurlbert still had the airstrip where Jimmy Doolittle's crew practiced take-offs in the B-25s. They had a white line across the runway to denote the end of a carriers deck. Never saw it but my brother was an insurance adjuster out there and said he had seen it many times. Cool bit of history.
From Wiki:
"Under the tutelage of Naval Aviators from nearby NAS Pensacola in March 1942, Lieutenant Colonel Jimmy Doolittle and his Raiders practiced taking off with their B-25 Mitchell bombers on a short runway, demarcated to represent an aircraft carrier deck, using the short cross-field runway near the southern end of Hurlburt Field's main runway. This complex is now named the Doolittle Runway. Other Eglin fields, including Wagner Field/Eglin Auxiliary Field No. 1, and Duke Field/Eglin Auxiliary Field No. 3, were also used during this training.
For the 2008 gathering of Doolittle mission survivors, six crew were present for recognition in Fort Walton Beach, Florida, culminating in a reenactment of the training sessions by three civilian-owned B-25 Mitchells at Duke Field on 31 May. Navy personnel from NAS Pensacola, as flight deck "shirt" crew, represented that service's contribution to the Tokyo mission."
If you look up Sue-Bee Line Front End Alignments in Pensacola, you can meet and talk to one of the B-25 pilots, if he’s still alive.