Having used Superfast Ferries for the last few years, I feel that I can wholeheartily endorse this as a method for folks living in Scotland to get to the Alps without enduring hundreds of miles to reach a Channel Ferry/Tunnel.
The Superfast Ferry runs daily from Rosyth (outside Edinburgh) to Zeebrugge, setting off at 17:00 hr and arriving at 11:00 the next morning.
Facilities on board are great and you arrive well rested for the roads ahead.
The good bits are that your bike is well looked after, you get a great night's sleep, food is fine and cabins (if you choose one) are quiet.
The downside is cost - I am paying approx ?220 return, sharing a two berth cabin. However, time is limited and some cost can be offset against fuel and accommodation en route.
Interested? see Web address below: