Terry,
I also launch from Wick virtually everytime ( and sometimes from Lymington ). As Adam says the slipway needs the lower section repairing, but it is an easy slipway to use. I launchy a 17ft Orkney there with a Mondeo with no problem.
As Adam says you have to keep to the channel in the harbour as it is very shallow ( even in the harbour ) and going over the sandbar outside the entrance is also something to be wary of ( it gets very shallow a suprisingly long way out ).
Same as for Adam with regard to assisting ( weekends best for me ) and if you want a "buddy boat" to go out with.
Only attempted to launch from Mudeford once but someone got the tide times slightly wrong