Many thanks for all the info, Chaps!
It looks as though it'll be the Rudd and Mullet options- both because of the time factor, and because I've found out how much Herself has forked out for the week! (porridge and lentil curries til doomsday!)
My rudd PB is pretty feeble, and I've never had a mullet (went bald before they came "in"), so I shan't be short of a challenge for the week; and as Throop no longer appears to be day-ticket, and my memories of the Royalty aren't wildly fond, I shan't be weeping into my wallet!
I looked up Hamworthy/Rockley lake; it looks very deep, with only a couple of areas of gently sloping shallows, and surrounded by woodland. I suspect the shelter, the depth and the hot weather earlier this summer will have set up a very distinct thermocline, so unless I can find out where the "comfort zone" hits the slopes, I'll need to bone up on "up-in-the-water" techniques. I hope they like bread!
I'm starting to get quite excited!