To 'test the waters' means to gauge people's feelings or thoughts before taking further action, asking them to do something or committing to something. When you 'test the waters' you might be trying to find out if something is likely to be successful before taking action. This is an idiomatic expression used in social and professional contexts.

1. Before committing to a move to Tokyo, Robert tested the waters by going there on holiday first. It really helped him make his mind up.

1. I had an interest in journalism from a young age, but I wasn't sure if I would like it as a career. My internship at the newspaper was a great way for me to test the waters.
2. Instead of wondering whether the boss would implement your idea, why don't you test the water instead? Just go into her office and suggest it to her now.

1. The company tested the waters by issuing a limited release of the product into shops. It sold so poorly that they cancelled their planned large roll out and went back to the drawing board.