While tens of thousands of families travel to Florida each year to enjoy the beaches and sunshine, the Schmitt family take their annual holiday just a little off-shore in search of something else: treasure.

For several years now, the family of professional treasure hunters has been returning to search for gold in about 15 feet of water off Florida's aptly-named Treasure Coast. The region is home to several notable shipwrecks, including a dramatic 1715 event that claimed 11 Spain-bound galleons and the lives of over 1,000 sailors.

The Schmitts acts as sub-contractors to 1715 Fleet-Queens Jewels LLC, which owns rights to the site where the ships foundered 300 years ago. It's estimated that only a little over a third of the $400 million in gold and silver held on the vessels has been recovered –– leaving plenty of opportunities for professionals to reap the rewards.

Last month proved to be one of those moments. Diver Eric Schmitt was using a metal detector to analyze the seabed, when something caught his eye. Sweeping away the sand, he found one, then, two, then more than 50 gold coins. The haul, estimated to be worth more than $1 million, also included over 40 feet of gold chain and an extremely rare Tricentennial Royal coin minted in 1715. That one piece alone is estimated to be worth more than $500,000, with only six known to be in existence.

"Those are things you dream of finding a royal coin, finding a presentation piece. And there are people who have been doing this for 40 or 50 years who have never found one," Schmitt told CBS News.

According to Florida law, up to 20 percent of the rarest treasures will be displayed in museums, the rest will be split between the Schmitts and 1715 Fleet-Queens Jewels. The family, who in previous years has discovered 60 feet of gold chain and other artifacts, said that what they do is hard work — and definitely a passion.

"There are good times and there are bad times and this is definitely one of our good times," Schmitt added.

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Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Florida family discovers $1M in shipwreck treasure
The professional treasure hunters unearthed gold coins and artifacts from a 1715 Spanish shipwreck.