"...our new subs are being built off shore..." Better than buying old Brit Upholder class subs in 1998 that were way past being serviceable. Our lot bought several that tried to sink after catching fire, on the trip across the North Atlantic. So don't buy used kit from the RN.
"...we have aircraft that can use one..." CF's F-18's are carrier rated. As are the drivers. And we have no big boat to put 'em on.