MaxCorvette

I used 4mm birch wood for the ribs and stringers and 3mm birch ply for the hull plating.
The drawings are made for these thickness of wood.
Next time I'll use 3mm ply for the ribs and a mix of 1,5 and 3mm for the hull plating.
But if you're not an experienced builder don't use 3mm for ribs, they will break once or twice before the project is fnished.
And also for a gas cat weight is not a real issue, a slightly heavier cat will be a steadier cat.
Lighter is not always good if you want an allround fun boat.

here is a pic of my Cat.

Marcel