The problem with a 'fishing-boat' radar signature

What does it mean when a stealth warship is said to have the radar cross-section of a fishing boat?

Very little without a specific reference, because fishing boats vary enormously and large trawlers can have substantial radar returns.

Fishing boats range from tiny inshore craft to large oceanic trawlers covered in masts, rigging, and steel equipment. Those projecting surfaces can create a very large radar return. Saying a stealth warship resembles a fishing boat encourages listeners to imagine a small contact without defining the reference target. The phrase is publicity shorthand rather than a useful technical measurement. A meaningful comparison must at least identify the kind and size of fishing vessel being used as the reference.