A carved face on a museum wall invites a portrait-like reading. On a ship, that same object occupied a particular position within a much larger shape. Try giving both settings a place in your notes.
Begin with what survives
Look for a catalogue photograph that includes the whole surviving carving. A close crop may conceal a missing shoulder or broken base. The Royal Museums Greenwich entry for the Falkland figurehead fragment, for example, describes only a head and left shoulder rather than a complete figure.
Make a small outline of the surviving object. Use a dotted line for anything you are imagining; a blank space is preferable to a confidently invented arm.
Change the imaginary viewing position
Now picture seeing the carving from a quay, with the vessel between you and the sky. Which details might remain legible? Which fine marks would disappear? This is an observation exercise, not a reconstruction of that particular ship.
Finish with two captions: one describing the object in the gallery, another describing the questions its former setting raises. Keeping those captions separate lets the carving be both an artwork you can see and a maritime object whose missing surroundings still matter.