who does Santiago wish was with him? why?

Santiago wishes that Manolin was with him to help him hold the line.

“I wish I had the boy” the old man said aloud. “I’m being towed by a fish and I’m the towing bitt. I could make the line fast. But then he could break it. I must hold him all I can and give him line when he must have it. Thank God he is travelling and not going down.”