The Blackfly is a 14 ft by 4 ft lapstrake plywood dinghy that can be sailed and rowed. The Blackfly was designed by Bruce Taylor using the free software Hull Designer.
Blackfly is an open sailboat that is light enough to portage and cartop, and capable of carrying as much cargo as an ordinary tandem canoe. The result is a burdensome but lightly built craft, suitable for sheltered waters in fair weather. A good way to go is the use of a 75 sq. ft. standing lug sail. Here are plans to make one yourself.
The plans are available in many formats so there should be one that fits your needs.