May 2021 Treasure of the Month

Our Treasure of the Month for May, 2021 is special as it marks the 10th anniversary of the posting of our first Treasure of the Month in May, 2011. Our featured treasure for this month was recovered during the 2019 and 2020 dive seasons by the crew of the Mighty Mo captained by veteran diver Mike Perna. Our story begins in the summer of 2019 while the Mighty Mo was operating in the area known as the “Anchor Wreck”. The Anchor Wreck was named after an anchor that was found in the area that has yet to be identified.

Crewman Milan Kalekar displays a handful of fresh out of the ocean gold and silver coins as Captain Mike Perna looks on.

In 2019 Captain Mike Perna of the Mighty Mo recovered several (actually seven) gold coins (known collectively as “cobs”) produced by the Spanish colonial mint of Mexico City. All of the cobs were dateable to 1714. But, the astounding feature of the find was that all but one were “GRATS”. GRATS are specially minted Mexico City cobs that differ from other gold cobs minted in Mexico City in the year 1714. The GRATS, or date on reverse coins, were a single die series at the beginning of the 1714 mintage. The GRATS were condemned and did not last long as the single GRAT die was overstruck with a 1714 date before it was used very much.  At least one expert has concluded that no more than 1000 – 2000 GRATS were struck. Most gold cobs from Mexico City have dates on the front, or obverse, side on the coin. With GRATS, however, the 1714 date on the front is replaced with the word GRAT and the 1714 date is on the reverse.   Six of the seven gold coins found were of the GRAT variety. It is almost unheard of that so many of these special coins would be found together in one small group. In addition to the gold coins, over five hundred silver coins were also found many of them on the last day of the 2019 dive season!  According to Captain Perna, these coins were recovered in about 12 feet of water and under 5 feet of sand. All in all, just under 1,000 silver coins were found in the 2019 and 2020 dive seasons by Mike and his crew.

1715 Fleet Society - Lou Ullian Letter 1
GRAT found by the Real Eight Company in 1964. Note the full date on reverse. The Real Eight Company referred to these coins as a “Die 9 variety.”

In the 2020 season, Captain Perna went back to this same area and recovered another four gold coins, two of which were GRATS. So, over the two dive seasons he recovered eleven gold cobs, eight of which were GRATS. A truly outstanding find.

Figures 1-4 (below) are images of the four gold cobs found during the 2020 dive season. Notice how the coins in Figures 1 and 4 differ from the coins in Figures 2 and 3. The “1714” date on the front, or obverse, of Figures 1 and 4 is a distinctive die variety. Whereas, Figures 2 and 3 which are GRATS, feature the date on the reverse at the 12:00 position. Figure 2, however, has a faint trace of a date. Figure 3, has no date at all which was a common problem with this design, which was one factor leading to the elimination of this series.


Much of the information contained in this post is from a personal interview with Captain Mike Perna. We would like to thank Mike for taking the time to discuss his find with us. Also, special thanks to Director Emeritus, Ernie Richards, for other information used in this post.

1 thought on “May 2021 Treasure of the Month”

  1. I would commend to students of Fleet-era Mexican onzas coin #83173. It has one of best struck shield sides I’ve seen on any GRAT. Beautifully sharp, near full shield and crown, oMJ, VIII and DEI GRAT. If a collector can find a similar coin in the marketplace, he should be very happy.

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