When I was about 14 my older brother and I built a raft almost exactly like that. Most of it was constructed of salvage materials. We had no plans other than the idea that my brother held in his head. It just had a deck - no bench (or what ever that is). It did include the mount for an outboard motor.
My dad inspected it upon completion and was impressed (which was impressive all by itself!).
The next part is the most fantastic.....our folks allowed us to sail her around the lake! We lived on Lake Washington which is 22 miles long. We ran the perimeter of the lake, hugging the shoreline (trust is earned, not implicit!) and tying up under the overpass of the floating bridge at night. It took us the better part of three days to make the run. There are (or were) gasdocks at various locations so fuel and supplies weren't a problem. We never failed to attract attention wherever we went - it was quite the novelty craft!
We had a minimal tookit with us and had to adjust the tension on the guy wires that held the raft together but that was the only repairs or modifications we did. Dad made us carry lifejackets and a little firstaid kit.
The trip was a complete success and we arrived back home none the worse for wear. The raft that carried us safely (so to speak) was retired from active duty and anchored just offshore to be used as a swimming platform where it served many seasons.
Think about it - would you let your kids float away on something like that today?