The term "go out of depth" implies a situation where someone lacks the knowledge, skill, or experience required to handle a particular task, situation, or conversation. The opposite of this phrase can be described as being proficient, confident, and well-informed. Antonyms for "go out of depth" can include being knowledgeable, competent, expert, experienced, or skilled. When someone is knowledgeable or competent in a particular field, they are said to have a deep understanding of it, and the skills to tackle any challenges that may arise. Therefore, it is always advisable to seek guidance, consultation or training before undertaking any task or conversation to avoid going out of depth.