Becareful what point you wish to transit as you may be best calling Bournemouth.
This is why I am confused. In the past when holding over the BIA at FL50 I was talking to Bournemouth.
However, now I fly from somewhere else, and if routing to the Channel Islands via NEDUL / ORTAC the easiest option for me (other than skirting their airspace) is to climb to 3000 (to remain below N866) and transit Bournemouth from say Tarrent Rushton to Hengistbury Head and intercept the SAM radial (I forget which one).
As mentioned, a CTA is not a zone, and CAP413 doesn't clarify. If my initial call is for "zone transit" they may assume straight away that I want to transit their Zone which I don't.
If I were to go now, I'd call Solent and ask "to transit their airspace" or "CTA transit". I imagine I'd be told to call Bournemouth anyway, but it is only polite to call the agency listed on the chart
