Los Roques, geography.
The average depth of the Archipelago is between 8 to 10 meters, with a maximum of 50 meters. Similar to La Orchila and the Las Aves Archipelago, Los Roques is separated from the continental platform by channels which are over 1.000 meters deep and only 2 or 3 kilometers away from the archipelago. The majority of the keys are rather small in area. Cayo Grande 15.1 square km. is the largest in area and Visqui or Pulguita with 0.001square km. are among the smallest.
Many of the smaller keys are in a state of formation and they are seen as sand banks lacking in vegetation, this is why they are considered sand banks. Other keys are widely covered by mangrove and inside lagoons such as Espenqui and many of them have extensive beaches of white sand on the leeward side (contrary to the wind) like for example Carenero or Cayo Agua.
The waters which surround the archipelago are very clear and lacking in nutrients; the different shades of blue is due to the type of bottom where they are at. The transparency of the water is due to two fundamental reasons: the first one is the distance between the mainland and the archipelago which prevents it from being affected by the sediment flows of rivers, which provide to great amount of silt and organic responsible for the darker shades of water around the Terra Firme coast line of Venezuela. The second reason is the waters of the archipelago have low productivity and a low level of nutrients, in contrast with the waters of the Venezuelan east where the organic matter deposited in the bottom of the sea gets mixed with the water in the surface making it thus much more rich and productive, but at the sane time colder and not as clear. The "poverty" of the waters of Los Roques contrasts sharply with large extensions of coral reef, considered the communities of greater biodiversity on the globe.
The dry climate of Los Roques is a result of the influence of trade winds which blow from east to northeast and frequently from east to southeast, with an annual speed of 21,8 km/hr minimum of 19km/hr in November and a maximum of 25.2 km/hr in June with maximum rates of up to 47 km/hr. The relative humidity is 83% annual and rain takes place in the form of brief showers with an average of 256.6 millimeters; minimum 6,6 millimeters in April and a maximum of 52,2mm. in November. The average annual temperature is 27,7°C with a minimum of 26,2°C in June / January and a maximum of 28,2 ° in September. Winds east – west are predominant; average visibility is approximately 21 kilometers. Water temperatures are between 25 and 30° C with minimum records between January and February and maximum between June and October. Heatstroke is very high and the yearly average is 8,6 hours/day. Together with a steady and intense breeze and the high temperature (27°C) gives way to an intense evaporation.