For the hundreds of years since historical mining began in the New World, copious records of the annual production of both gold and silver were systematically recorded. These ongoing records have been maintained into the 21st Century. Working with NYC-based CPM Group (www.cpmgroup.com), UnderSea Recovery asked this precious metals consulting and research company to estimate how much gold and silver was likely to have been lost in shipwrecks during this 330-year period. The answers provided are quite extraordinary, and much of the following discussion is based on CPM’s response.
The weight (and hence value) of precious metals such as gold and silver are measured in troy ounces (abbreviated as “ozt”) rather than the standard (avoirdupois) ounce (with the more familiar abbreviation of “oz”). A troy ounce is 9.7% heavier than the standard ounce and there are 12 troy ounces in a troy pound (known as a “troy”) as compared with the 16 ounces in a standard pound of weight measurement.
Records relating to the world’s historical production of gold (since such records were kept) indicate that approximately 5.1 billion troy ounces had been found (mined) throughout the world. Of this amount, approximately 89% could be accounted for in gold bullion inventories, industrial use and jewelry, etc. Much of the remaining 11% (561 million ozt) was considered unaccounted for and CPM believes a great majority of this gold may well have been lost in historic shipwrecks within the world's oceans in the form of coins, ingots, jewelry, and the like.
Records relating to the world's historical production of silver indicate that at the end of 2002, a total of 56 billion ounces had been mined throughout the world. Of this quantity, approximately 61% had been accounted for in silver inventories, industrial use and jewelry, etc. Much of the remaining 39% (almost 22 billion ozt) was considered to be unaccounted for and, as is the case with gold, CPM believes a great majority of that silver may have been lost in the world's oceans.
The fact that so much gold and silver was mined throughout the world and cannot be accounted for certainly gives a lot of weight to the immense quantities of both of these metals that were known to have been lost in the world’s oceans during the 330-year period following the discovery of America in 1492. So, once lost, how can one ascertain the locations where these ships were wrecked? Thousands upon thousands of original records (such as ship manifests, port records, tax documents) relating to a large percentage of the lost “historic ships” can be extensively researched at archives located in Spain and other nations. When galleons were being loaded with gold and silver over a period of many months for their long voyages back to the Old World, Spanish authorities maintained meticulous records. Nearly every item that was loaded on these ships, including food, liquids and animals, was recorded. One or two copies of the ship’s manifest would always travel with the fleet while one copy was retained in the New World for at least a year prior to being sent back on another fleet and brought to Spain for safe keeping in the archives.
Despite extensive efforts to maintain this level of regulation by the Spanish Crown, temptations involved in handling so much wealth were irresistible and successful attempts to cheat the system prevailed. The high value of cargoes and extensive taxes on shipments made smuggling a tremendously profitable pursuit. As an example, one ship that ran aground near Spain in 1555 had a registered cargo of 150,000 silver pesos (4.7 tons). However, when later salvaged, 350,000 pesos, amounting to almost 11 tons of silver, were found. Therefore, it is quite obvious that contraband was very common aboard the galleons and, according to one source, the amounts sometimes equaled as much as 50% or more of the registered cargo.