航拍无人机从沙质海床上的海藻斑块上空飞过，海水中点缀着岩石，水质清澈，景象清晰。

n drone footage shows seaweed patches spread across a sandy seabed in clear shallow water. The clusters of algae create irregular dark patterns against the pale bottom. Visible underwater texture suggests a quiet nearshore ecosystem without animals or human activity. The scene supports marine vegetation, seabed mapping, and transparent coastal water themes.