The beach can be divided into distinct zones based on its physical characteristics. The upper beach consists of dry, soft sand leading to the primary dune line. The intertidal zone features a mix of fine sand and, notably, a sandstone reef that creates pools and channels at lower tides. The surf zone transitions into the nearshore waters of the Atlantic Ocean.

The most significant underwater structure is the sandstone reef located within the intertidal zone of Praia de Baixa Grande. This reef formation creates channels, pools, and varied bottom topography that can attract marine life. Anglers targeting the surf zone may find productive areas near and around this reef structure, as it provides habitat and ambush points for fish.