Like souls they float in a safe harbor sheltered from the force of the sea. 

The souls of the sailors enter their boats still and resting on the sea. 

They float on the depths of nothingness filled with the light of their lives.

 Quiet souls now protected by the port after having crossed 1000 stormy seas.

 Resting souls.

"Boats are souls on the sea" is a poetic or metaphorical phrase of mine that attributes a sort of soul or life to boats sailing on the sea. With this sentence I want to suggest a deep connection between the aquatic element and boats, implying that boats have their own essence or spirit similar to that of people.