The phrase "burns boats" is a metaphorical expression used to describe someone who destroys all the available resources or options. However, there are several synonyms that can be used instead of this phrase, depending on the context. One such synonym is "severs ties" or "cuts off connections," which implies a deliberate action of breaking ties with someone or something. Another synonymous phrase is "shoots oneself in the foot," which means to do something that ultimately ruins the chances of success. Additionally, "sabotaging" or "undermining" can be used to describe a deliberate act of causing damage or harm to something or someone. In essence, while "burns boats" may be a popular idiom, there are many other ways to describe the same meaning.