CAS should have radar (but I can't find the definitive reference...) and type of air traffic service should be specified (somewhere in MATS Part 1...). ATCOs managing CAS are under direction to specify Radar Control Service, in the same way that Type of Service is specified outside CAS. RCS is regardless of whether the aircraft is being vectored or whether the pilot is navigating the aircraft. VFR pilots are usually left on own navigation as far as possible for obvious reasons but will still be told 'Radar Control Service'.
Originally Posted by StuartUK
we received a radar service upon entering Solent CTA (which was fantastic as this was the first time I'd ever had this)
Er...don't get too excited about this...it's merely routine...