"BRITANNIA RULES THE WAVES" Medallion / Medal

Found this medallion / medal in a box of old British coins and can't find anything about it, so was hoping someone might recognize it. The medallion is about the size of a U.S. Kennedy half dollar and features a maritime theme with an engraving of a battleship, complete with a prominent mast and smokestacks, sailing on the waves. Above the ship, there's an inscription that reads "BRITANNIA RULES THE WAVES." To the right of the ship, there's an emblem that appears to be a naval insignia. The medallion also has a rectangular loop at the top, flanked by two small lion heads. Any info would be cool, because it is really an interesting medallion! Thanks!!