I agree with Dan. It's unrealistic to expect someone totally unfamiliar with a boat to walk aboard and come back without the possibility of some troubles even if the vessel comes back in as perfect a condition as possible. Charter
companies have the infrastructure to make your vacation
easier and assure that boat problems can be handled quickly without a lot of financial exposure by either party.
The idea of a reciprocal arrangement could work. You come sail with me a week and I come and sail with you for a week. That way each boat has a familiar skipper
that knows the best places to go and the crew have a great time twice! In this way you can arrange an exchange to sail in places you might not be able to get to easily. You get local ground help and provisioning
. For a one week trip you'll get additional time on the water
since you won't waste a whole day doing provisions and check out. You just have to have an agreement on when and where you like to go. You divide many expenses and each get a week in a great new place and week to show new friends the best places you know.