The phrase "be knee deep in" is often used to describe being heavily involved or overwhelmed by a particular task or situation. Fortunately, there are many synonyms that can be used to vary one's writing and speech. Some alternatives include "be up to one's neck in," "be swamped by," "drown in," "immerse oneself in," "become engulfed in," "be buried in," and "be consumed by." Using these synonyms can add color and depth to one's language, making it more dynamic and interesting. Whether writing a novel, giving a speech, or engaging in casual conversation, using varied vocabulary is always a plus.