Everything on a boat this size can hang off one small fused panel, and the discipline is in the terminations rather than the diagram.
Sizing it
Add up what is actually on at once: two nav lights and a cabin light. It is a handful of amps, and undersized cable is still what causes most faults.
Terminations
Tinned cable, heat-shrink crimps, no solder in a run that flexes. Every joint above the sole where you can reach it.
Where the panel goes
The navigation station to starboard is dry and reachable. The locker under the port berth is neither.
