Construction Idea of Curved Plate

Hi,

I am thinking about the steel construction of the following shape. But I am confused about the structural construction of this. How to stiffen this shape? I just would like to get some idea. I have seen many yachts have curved shape like this. But I was thinking where two plates are joining, the space is very narrow to welding. For example if I stiffen with plates inside with some lightening holes, I find too difficult to weld along the red line. Do you have any suggestion? How actually these types of shapes are built?





For example take a look at this vessel super structure shape, How it is built at the front?

 

It's simple actually; closure plates, plug welds, and flaying surfaces. Look closely at the photo and that is exactly what you see.

Edit to add: Here is a similar example for a rudder.

 

Thank you so much.