Small steel boat

Hi, I have a number of pieces of steel salvaged from a houseboat remodelling job I did.

I've not built a boat before though have renovated a few.

My plan is to build a 12 foot flat bottom boat, with a plumb bow. I have nearly all the steel, 6mm (1/4) for the bottom and 3mm (1/8) for the sides,

The boat is to be used (and left) in the river (Thames) where I live. It's non-tidal and very flat. I calculate that with an inboard diesel the boat will draw 200mm (8") leaving a freeboard of 550mm (22").

It'll weigh best part of a tonne, but that doesn't matter if she stays in the water.

Can anyone throw any light on my plan, your welcome to scupper them!

 

What do You think about it?
This is exactly narrowboat cabrio.
Take narrowboat bow, and narrowbot stern and You have exelent open boat.
Easy to made.
This boat is biger than 12 feet, but You can have problems with wight if You want exactly 12 feet.
18 to 20 feet will be in my opinion optimum for 3mm sheet metal