Spaceship wreck, the survivor is in a lifeboat of some sort that has AI system, grabs hydrogen molecules for power as it travels. The survivor lives on life support, learning from the AI library, knows that death will come. The AI then rebuilds or grows the body into another being using the instructions from the original, continuing until it crash lands on a planet, in which the final body emerges from the ocean... I read the book in the early 90's in a collection of older sci-fi shorts my grandfather had, I estimate they were 20+ years older. Now my kids are into the old sci-fi...