Three points:-
(1) I wasn't asking for a clearance, only for a FIS.
(2) Solent was less busy that Shoreham, insofar as the RT was quiet enough to speak to them.
(3) My route took me within a mile of Solent's airspace, and nowhere near Goodwood. In that context, speaking to anybody but Solent wouldn't have made much sense.
On Foxmouth's more detailed point, I elected to change at Selsey Bill, when I was close enough to be an issue to Solent, not "just past Shoreham". My routing was then inland, on a direct track to Popham, not along the Solent.
G