Vanishing island refers to any permanent island which is exposed at low tide but is submersed at high tide

High Tide

High Tide was a band formed in 1969 by Tony Hill , Simon House , Peter Pavli and Roger Hadden .-History:...

. Vanishing islands occur globally. There are seven vanishing islands in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

 and several in the San Juan Islands

San Juan Islands

The San Juan Islands are an archipelago in the northwest corner of the contiguous United States between the US mainland and Vancouver Island, British Columbia, Canada. The San Juan Islands are part of the U.S...

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Cryptozoology

In early times, seamen were confused by this phenomenon and invented explanations for it, usually involving a massive sea monster that would let a crew land on its back before submersing itself, drowning the crew. Notable examples of these include the aspidochelone

Aspidochelone

According to the tradition of the Physiologus and medieval bestiaries, the aspidochelone is a fabled sea creature, variously described as a large whale or sea turtle, that is as large as an island. The name aspidochelone appears to be a compound word combining Greek aspis , and chelone, the turtle...

, Fastitocalon, Jasconius, Lyngbakr

Lyngbakr

Lyngbakr is the name of a massive whale-like sea monster reported in the Örvar-Odds saga to have existed in the Greenland Sea. According to the saga, Lyngbakr would bait seafarers by posing as a heather-covered island, and when a crew landed on his back, he sank into the sea, drowning the crew...

, Hafgufa

Hafgufa

Hafgufa is the name of a massive sea monster reported to have existed in the Greenland Sea which was said to disguise itself as an island or pair of rocks rising from the sea...

, and various accounts of the kraken

Kraken

Kraken are legendary sea monsters of giant proportions said to have dwelt off the coasts of Norway and Iceland.In modern German, Krake means octopus but can also refer to the legendary Kraken...

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