Biscuits and gravy
The word you are looking for might be "raft."
A raft is a simple log boat. It begins with the letters RA.
That sounds very uninteresting! (Assuming you take 'log' to mean a large chunk of wood, perhaps 'log' has another meaning that I don't know.)
A canoe or boat dug out from a large log., A place dug out., A house made partly in a hillside or slighter elevation.
a log
Ancient sailors would toss a bit of wood, called a log, over the side, and by reckoning the time it took for the boat to pass the log they could estimate the speed of the boat through the water. From this comes the "log", or log book, in which the progress of a vessel is recorded.
Probably a floating log.
The dugout boat is the oldest known to archaeologists. This type of boat was created by hollowing out a log.
Droll; comical; amusing; laughable., A clinkerbuit, narrow boat for sculling.
Early man through a log into the sea, and then sat on it . That was mans first boat.
raft shaft
History says that early man first sat on a big log of wood or on a tree as a boat.