The ships were returning from a mission to Cuba when they sank during a hurricane off the coast of Florida near Sebastian.
In 2015, Martinez was part of a group that found more than 300 gold coins from the 1715 wreck, a haul valued at $4.5 million, Florida Today reported.
Some treasure hunters estimate there is still hundreds of millions of dollars of gold, silver and other artifacts still waiting to be found off the Atlantic coast.
"A hurricane came and pushed them all onto the reefs of the Treasure Coasts. And that is why we are called the Treasure Coasts, because of these shipwrecks," Nichole Johanson, director of Mel Fisher's Treasure Museum, told WPTV. "The late '50s is when the coins started turning up on the beaches and salvagers have been salvaging them ever since. Treasure has been found consistently."
Martinez does not intend to sell the coins. He and his group have divvied up the items, as well as donated some to museums.
"I don't sell any of our coins," Martinez told WPTV. "It's like a piece of history."