Ballimore Bothy

You can rent out the bothy next to the Oystercatcher bar and restaurant.

The bothy is owned by Miranda the baroness, you can book to stay most of the year and there are other places available on the estate too. It's got good showers as well.
Only downside is that it can be quite pricey.

It is a great experience to stay at the Bothy, on the shores of Loch Fyne. It has several different rooms to choose from. Please note though, although there’s a kettle, there’s no kitchen as such.
There is a pub a few meters away though, named the Oystercatcher, providing great food. Fresh seafood as well as other things on the menu. Outside seating area. The entire pub has just been renovated and a new team in the kitchens. Well worth a visit to this stunning area, that few know of. The sunsets can be glorious in the summer.
You are able to sit on the beach (a mere few metres from the pub and bothy!), directly on Loch Fyne.