I can’t remember a lot of the body of the book but it’s set in an undetermined place in space (not Earth). It had a boy who was orphaned by his mother because he had some mental ability (empathic?) which scared his mother. He ends up meeting some guy that recognizes his ability because he put him in a situation that tested said ability (something to do with a wild animal hunting the boy down and the boy uses his skills to survive). Boy eventually becomes a space pilot on long range missions where they go into suspended animation.
I distinctly remember the last part of the book. The boy (now an adult space pilot) is shuttling a bunch of colonists on a long-range mission and the ship is struck and badly damaged. He has a number of surviving colonists but only half as many recorded brains/consciousness and he has to figure out how colonize this planet. He ends up waking a few people every so many decades and introduces them into this new and primitive colonized group, then he goes back to the spaceship (which is underwater) and goes back into suspended animation, and does this for hundreds of years until all the colonists have been integrated into this society.
The culture makes up a legend of this guy bringing them “lost members” of their people, teaching them skills and then going away until eventually the stories turn into myths and all the while, the spaceship is sitting at the bottom of the deepest part of their ocean and he is in permanent suspended animation.