AMAZON RIVER WATER LEVEL PERIODS: Water Level increasing period: November to June – Maximum Level: June to July Water Level decreasing period: July to October– Maximum Level: October to November SOUNDING CORRECTION ABACUS - AMAZON RIVER WATER LEVEL: The information about Santarém River Water Level for use with the Sounding Correction Abacus, that are in this chart, are disseminated daily by radiotelephony using the Ner Rede Nacional de Estações Costeiras (RENEC), from Belém, Breves, Santarém, Parintins, Itacoatiara e Manaus. These information can lso be obtained a at the internet website www.mar.mil.br/chm/avgantes/avradio/amazonia.htm or directly at the Serviço de Sinalização Náutica do Norte – Belém, Capitania dos Portos da Amazônia Oriental – Belém, Delegacia da Capitania dos Portos – Santana, Delegacia Fluvial – Santarém, Capitania Fluvial da Amazônia Ocidental – Manaus and Serviço de Sinalização Náutica do norte – Belém.