this canal, home to the the island of bom jardimand part of the reserva biológica e arqueológica de guaratiba (renamed  reserva biológica estadual de guaratiba) borders the northern side of the marambaia, and is in itself a natural treasure.

marambaia is jointly administrated by the brazilian navy and the army. it is used by all branches of the brazilian armed forces for numerous purposes, such as for military training and arms experimentation, chiefly by the marine corps.

the centro de adestramento da ilha da marambaia (cadim) has been operating there since 1981. the sandbank is utilized by military staff, their families and guests as a leisure area - many high-ranking politicians use these shores as resting areas when in rio for official business.