steel canoe design help

well i got inspiration partly from that one for sure. but he build it with 1.5mm thick and i am doing it will 0.8 mm. yes i ruined one sheet of metal to get my hand used to it. but it was unnecessary as after 1M of welding me and my brother took the hand to it, but there is a catch i go 4mm a time and after 0.5sec i forward another 4 mm. Yesterday i talk to a friend of mine and he suggested that a 0.4 or 0.5 mm can be welded with acetylene torch but i don't know how strong is the bond. so i think if this goes well i will try the 0.4 or 0.5 mm. Tthe guy there also said the canoe was very stiff and its dam true. with 0.8 mm if i weld a piece of steel in shape there is way to damage it.

thanks for the comparison i didn't knew it. as i am new here.