This Georgian era ring dates to a time when the British Royal Navy was battling Napoleon's French fleet. Very likely made as a love token for an admiral's wife to wear while he was away at sea.
Being that ivory is a fragile material it is an extremely rare survival of a micro ivory carving. The warship is set under crystal on a hand painted ground of waves with flat cut garnets surrounding the bezel.
A similar ring can be found at The British Museum in London. English. Late 18th century.