yesscotland.com says:
Fantastic sailing areawith easy access to the Idle of Bute, Kames, Tighnabruaich and across the peninsula to Loch Fyne. You can also get a ferry to Tarbert, Loch Fyne from Portavadie so a stay in the Auchenlochan area is a good base for a few days stay. The best route to this aea is by ferry to Dunoon and through Glen Lean and Glendaruel and down to A8003 to Tighnabruaich. Highly recommended.