Please allow me to muddy the waters by giving you the definition of SVFR Flight from The Manual of Air Traffic Services Pt 1.
And I quote.....
"(SVFR is) a flight made at any time in a control zone which is Class A, or in any other control zone in IMC or at night, in respect of which the appropriate air traffic control unit has given permission for the flight to be made in accordance with special instructions given by that unit instead of in accordance with the Instrument Flight Rules and in the course of which flight the aircraft complies with any instructions given by that unit and remains clear of cloud and in sight of the surface".
There's also a nice one line description in Pooleys....
"Clearance for SVFR flight in the UK is an authorisation by ATC for a pilot to fly within a Control Zone although he/she is unable to comply with the Instrument Flight Rules".
Bearing in mind any licence limitations, ATC will not issue a SVFR clearance for a fixed wing departure from a Control Zone if the met report gives a viz of 1,800m or less and/or the cloud ceiling is less than 600ft.
But the above can also be varied locally.
The two units which I am very familiar with and in current practice of issuing the odd SVFR clearances have the following restrictions....
Airfield 1)
Inbound... reported met viz must be 10km or more, and the lowest reported cloud 1,200ft or above.
Outbound... reported met viz must be 1,900m or more and cloud ceiling 600ft or above.
Airfield 2)
SVFR clearances inbound or outbound to fixed wing are not to be granted if the reported met viz is less than 3km or the reported cloud ceiling is less than 1,000ft.
SVFR is a much misunderstood subject and I can see why many find it confusing, but it really is quite simple. IMHO
WF.
p.s. FBW, no problem from here following Bookworms line of thought.
p.p.s. and I can confirm that Bookworm is a pilot as well