The Royal Navy’s 12th Submarine Flotilla had it headquarters, HMS Varbel, located in the 88 rooms of the requisitioned Kyles Hydro Hotel, which overlooked Port Bannatyne.
This was the only British base for midget submarine and human torpedo training.
The Navy used the protection of the port and the secure waters of Loch Striven to the north for sea trials and training exercises.
The exercises mostly included beach reconnaissance training on Port Bannatyne as well as navigation and pilotage.