Diction

1. Low or Informal Diction:
"... I only climbed on the spare spar and leaned over the rail as far as I could, to bring my eyes nearer to that mystery floating along side."

2. Elevated language or informal diction:
Opaque: not able to be seen through
Elongated: usually long in relation to its width
Phosphorescent: something glows with light without becoming hot to the touch
Elusive: difficult to find, catch, or achieve
Cadaverous: resembling a corpse in being very pale, thin, or bony
Ghastly: causing great horror or fear
Immersed: dip or submerge in a liquid

Paraphrase: The side of the ship made a hazy belt of shadow on the darkling glassy shimmer of the sea. I saw at once something extended and pale floating very close to the ladder. Before I could form a guess a faint flash of shimmering light, which seemed to issue suddenly from the naked body of a man, flickered in the sleeping water with the intangible, silent play of summer lighting in a night sky. With a gasp I saw revealed to my stare a pair of feet. like a resting swimmer, the sea lighting played about his limbs at every stir, and he appeared in it terrible, silvery, fishlike.

3. The elevated language contributes to the tone to make it sound more formal and more mysterious. Paraphrasing the passage affects the tone in a casual way. It sounds less formal and when reading the passage, it's not as intriguing as reading elevated words since it makes it sound better.

4. Abstract and Concrete Diction:
Opaque belt of shadow, Phosphorescent light, A headless corpse, and A board livid back immersed right up to the neck in a greenish cadaverous glow.

5.The author chose to leave the captain, the ship, and the crew nameless in the story because he wanted the readers to keep thinking and be clueless as to who was being described. The elevated words are the ones which unveil what the objects are and how they look.

6. Denotation and Connotation
The denotative meaning of the title "The Secret Sharer" is of the person who talks about their side that other people don't see, which is dark.