According to Flightradar (yes, I know) it had positioned to overnight in Norfolk VA (another naval centre), left on time at 0600 for a 90 minute flight to Jacksonville, and was due to leave there, contnuing as same flight number, at 0930 for Guantanamo but never got away until 1500, getting on for 6 hours late. Wouldn't have crew changed at Guantanamo, it's about a 2 hour flight each way but I wonder how long the crew had been on duty, arrival back at Jacksonville being more than 12 hours after they were due to leave there. Would be interesting too to learn what held them up.