Hi daveb47, welcome. We go out in the Solent and and launch from the public slip at Mudeford Quay, Christchurch. Can be a bit tricky at low tide but recovering the trailer after launching and recovery is easy enough with a length of rope between car and trailer!
It also gives you instant access to Christchurch Bay, the Solent and IOW, plus Christchurch Priory. There is a great pub - The Haven Inn right next to the slipway serving excellent food and ales and the quayside is a real hive of activity during the holiday season. I highly reccomend.