Found 15 Costal CC0 textures in library

Aerial Beach 01
Aerial Beach 02
Aerial Beach 03
Aerial Sand
Brown Planks 03
Coast Land Rocks 01
Coast Sand 01
Coast Sand 03
Coast Sand 05
Coral Gravel
Coral Ground 02
Coral Mud 01
River Small Rocks
Wood Planks Grey
Worn Rock Natural 01