Mid kent fisheries still exists mate, although you are right Chillham Mill is now a syndicate and it costs £750 a year. personally i can not justify that sort of money but could pay in the region of 500.
as previous answer start deep and cut off bit by bit. If you see carp just below the surface then personally i would start at 5 and half foot, to measure approx 6 foot you can use half your rod. (common sense i know).