Final answer:
The tone conveyed by Orson Welles in the metaphor 'solar driftwood' is mysterious. The language used in the passage creates a sense of uncertainty and unknown.
Step-by-step explanation:
The tone conveyed by Orson Welles in the metaphor 'solar driftwood' can be described as Mysterious. In the given passage, the men in the boat are experiencing a sense of uncertainty and unknown as they are stranded at sea. The language used, such as the description of the sea changing color and the mention of the forest being interminable, adds to the mysterious and eerie atmosphere.