I saw this going down the river yesterday. They had 2 canoes connected
together with an outboard on the rear connector beam. Looked
interesting.
They were about 3 feet apart and if the connector link is solid, it
looks like a pretty stable platform for what it is.

http://gfretwell.com/ftp/canoe%20cat.jpg

Greg, there's people that do about the same thing with Jon boats here on the wabash river. Weird but neat in a way