Tests waters is a phrase commonly used to describe the act of trying something out to see how it goes. Antonyms for tests waters would be phrases that describe a decisive, committed approach to taking action. Words such as "dives in," "commits," or "acts boldly" come to mind. These phrases indicate a no-nonsense, confident approach to making a decision and taking action. It is important to remember that while testing the waters can be a valuable strategy, sometimes taking bold, decisive action can be just as important for success. Knowing when to switch from testing waters to taking action requires insight, courage, and good judgment.