CULEBRA, the smaller of two islands lying in the Virgin Passage immediately E. of Porto Rico and known as the Islas de Passaje. It is about 18 m. distant from Cape San Juan and rises from the same submerged plateau with the larger islands of the Antilles. Its extreme dimensions are 3 by 6 m., and its surface is low and comparatively uniform, which gives the prevailing winds an unbroken sweep across it. For this reason the rainfall is limited to a short season, and the population is compelled to store rainwater in cisterns for drinking purposes. Its soil is fertile, and cattle, poultry, vegetables and small fruits are produced. The island has been a dependency of Porto Rico since 1879, when its colonization was formally undertaken, and it is now described as a ward of the Vieques district of the department of Humacao. In 1902 the American naval authorities selected the Playa Sardinas harbour on the S. side of Culebra as a rendezvous of the fleet and marine encampments were located on shore. The strategic position of the island, its healthiness and its continued use as a naval station have given it considerable importance. Its population was 704 in 1899, which had increased to nearly 1200 in 1903.