CYOA involving shrinking, seeing other universes, and then eventually arriving on a boat

I read a choose your own adventure book when I was a kid. In one of the adventures, the main character shrinks and gets to the molecular level. They keep shrinking and then they start to see galaxies, another solar system, planets, and then eventually they shrink down to the level of other people and they find themselves inside a boat on an ocean with someone talking to them.

Does anyone know what this book is?

by aithinktank