Hi @MASV Welcome to the Forum
These are some suggestions regarding achieving your objective. S3D often has multiple routes to the same result.
Lofting as suggested by @JST just needs the Profiles of the Design to be set out along the Keel Line and for the Bow and Stern Profiles to be created from the inner faces of the respective timbers.
Lofting will create a Solid Body that could be Tools > Shelled to create the Skin.
The Access Aperture could be formed by Tools > Subtract by creating and using a ‘cylinder like’ Body.
This uses only 3 Profiles, is Shelled to [IIRC] to 6mm Thickness and used a simple Cylinder to for the Access Aperture:
The Stringers can be formed:
Uniform Section - Tools > Sweep the appropriate Cross Section Profile of the Timber along a Curve
Non Uniform Section - Tools > Loft along a Curve
Add > Construction Plane was used and given a thickness of 0.001mm to form a Body.
Tools > Subtract and Keep Original [switch at top left].
Positioned appropriately this was used to create a Horizontal Cross Section to provide the Curved Edge that can used to create the Stringers. Of course the Stringer Profile will have to be positioned to accommodate the Skin Thickness:
If you need more help just shout.