How about Inverness?
Aberdeen to Inverness is about 110 miles (Aberdeen to Inverkip is 180 miles).
You then have access to the Beauly Firth, Moray Firth, Cromarty Firth, the rugged coastline of Caithness you could even make Orkney in a day. You can go through the Caledonian Canal into Loch Ness and through to the West Coast.
The link for Caley Marina in Inverness (with a great chandlery etc.) is as follows: http://www.caleymarina.com/frame.html
Keith (you could always pop in and see me) Hart