The crystal blue water of St. Thomas took center stage on this week's episode of "The Bachelor." But, where is this tropical island located, anyway? St. Thomas is part of the U.S. Virgin Islands in the Caribbean. The Virgin Islands include four larger islands and 32 smaller islands and islets. This particular island is a stunning display of Caribbean rainforest, white sand beaches, and crystal water. It is frequented by cruise ships, which can be spotted in several places where Nick Viall takes his date(s) in episode six.

Island of thieves

St. Thomas was originally inhabited by the Ciboney tribes, the Taino or Arawak tribe, and the Caribs.

Indian habitation here was also recorded in the 1500s, however these numbers declined due to plagues brought by Spanish settlers and conquerors. These indigenous groups no longer exist in the Virgin Islands.

Christopher Columbus is credited with the island's discovery. He was reportedly not impressed by the island and left it for Puerto Rico. As an unprotected territory, it became home to many pirates. In 1691, the Danish West Indian Company received permission from King Christian V to occupy the island. They sent over a ship of convicts, but could not rely on their labor and soon reached out to colonists from neighboring islands and relied on African slave labor.

In the 1700s, sugar became the popular crop.

After some squabbles with the British, St. Thomas became a free island in 1815. Tourism through sea travel later sky-rocketed in the 1950s.

Blue, sick water

The blue water surrounding the island may have been one of the only uplifting things about episode 6, so what exactly causes it? Ironically, blue water may be beautiful, but it's actually less healthy.

The Caribbean appears blue because the water is able to absorb red, yellow, and green wavelengths due to the lack of plankton and other particles. In order for the ocean to maintain a healthy ecosystem, plankton is a very important part of that equation. What appears flawless from the outside is very sick on the inside, perhaps making St. Thomas an appropriate setting and metaphor for this week's episode.