Hi Paul,
Have you thought of Chichester Marina ? I know it is a bit further East than the area you are looking at, but the facilities for trailer sailors are excellent. You launch into the locked marina, so no tides or time restrictions. There is a pontoon on the slipway to make life easier, water hose and outboard flush tank for cleaning down on recovery. The marina has top class toilet and showers etc. The prices are very reasonable, slipway charges are £19.00 for launch and recovery, trailer storage is £5.75 per week, there is no charge for car parking. Berthing is about £14.00 - £17.00 per night all in. All this in a beautiful rural setting with plenty of rigging space.
The draw back is you have a 45 minute motor up the river and have to cross the bar. But if you time your exit right, you will not even notice it.
I have based our summer cruise there for the last two years and we are doing the same again this year, starting 10th August. There will be four boats this year.
They have a web site, just search for Premier Marinas and select Chichester Marina.
Hope this is helpful
Fair winds,
Graham Ebb
235/25 Blue Jazz