Best cheap portable speaker that you can hear underwater?

Me and my roommate are trying to create a great party space in our backyard, but since we are high school freshmen, we aren't exactly rich. Between his and my jobs, we make only around six thousand a month, most of which goes toward rent, utilities, groceries, and booze.

That being said, our backyard pool is a popular attraction but the most common complaint we get is that people want to be able to hear the party music while being under water, but we don't have a speaker that can do that. We have a hookah that can be used underwater, so even if people didn't mind the brief interruptions from the music, we think it would be such a sick vibe to be able for people to be able to dive into the pool, hookah underwater for a bit, all while hearing the music.

Is there a portable speaker that we can put underwater and sync with the rest of the music so people can hear the tunes with no restrictions?