The phrase "go to the bottom" can have various synonyms depending on the context in which it is used. In terms of sinking, it can be substituted with "sink," "submerge," or "plunge." When referring to the idea of understanding the full extent of something, it can be replaced with "dig deep," "investigate thoroughly," or "get to the root." If talking about the idea of reaching a low point, it can be exchanged with "hit rock bottom," or "reach the nadir." Overall, the use of synonyms can help to diversify the language and make the writing or conversation clearer and more engaging.