test the water
test the waters

He said the department would not test the workers or the water in the building.

Why do so many of us feel the need to test the water first?

The way to find out is to test the water, he added.

But obviously he'll have to test the water at some point.

But perhaps the time had come to test the waters with him in a different way.

So far, none have come forward, though some are testing the water.

She decided it was time to test the waters, so to speak.

And you are the person they send to test the waters.

Tonight he had tested the water, she was sure of it.

"The industry really should test the water in these tanks."