The enormous pattern formed around a dew pond in a field and has left crop circle experts scratching their heads for a meaning.
The design echoes the giant jellyfish which appeared in an Oxfordshire field in early June, sparking conspiracy theories about the meaning of the huge number of patterns appearing in fields across the country.
Karen Alexander, a crop circle expert, said: "This is the first crop circle in the world to include real water elements, so it is very exciting.
"The area of Wiltshire where it has appeared is known its chalk hills and for being quite dry land, so it is even stranger that it should appear there.
"We believe it is a close relative of the jellyfish crop circle which appeared earlier in June, but beyond that we are still trying to decode the message of it.
"There are a myriad of theories about what these crop circles are trying to tell us, but at the moment we are no closer to knowing the truth it is incredibly exciting."
Crop circle theorists known as 'croppies' - believe the patterns are created by UFOs during nocturnal visits, or caused by natural phenomena such as unusual forms of lightning striking the earth.