A sandbank is a raised area of sand in a river or sea, often just under the water.
Sandbanks can be dangerous for boats, but they can also be a nice place to relax on the beach.
Examples:
The sandbank is just under the water.
We can see the sandbank from the boat.
The sandbank is a good place to find shells.
The sandbank is like a secret island.
The sandbank is a great place to play and relax.
The sandbank is a nice place to have a picnic.