I think there would be little problem with doing this. There may be a different set of problems to be overcome but they have already been addressed in other industries.

The hoods on pick-up trucks are made of aluminum and they are extremely light and strong. The amount of material would be about the same as this (Inner bracing and outer skin.)

You could glue the panels together or weld them (computer welding would be great but impractical.) and then glue stiffening braces inside or you could put a crown in each individual panel to strengthen it. You could use beading to add strength also and if you ran it the length of the boat it would help in tracking.

Corrosion could be handled with a good quality paint or just a clear coat.

Give it a whirl!! It would be interesting to see your results.

Ian