The coins being minted in Mexico City and dated 1782 or 1783 when visible. The obverse carries the bust of Spain's Carlos III while the reverse shows the Spanish arms flanked by the Pillars of Hercules. The weight of each coin typically varies between 16 and 22 grams in relationship to its degree of salt water corrosion.

These historic coins were among 400,000 such pieces that were lost in the Gulf of Mexico while being transported from Vera Cruz to New Orleans aboard the Spanish brig El Cazador. The treasure, meant to bolster colonial Louisiana's cash-starved economy, lay on the sea floor until its accidental discovery in 1993.