Confusing Dialogue in Ernest Hemingway's The Old Man and the Sea

Hello,

I am reading The Old Man and the Sea by Ernest Hemingway and I came across this confusing dialogue between Manolin and Santiago:

(Manolin) "Where are you going?"

(Santiago) "Far out to come in when the wind shifts. I want to be out before it is light."

(Manolin) "I'll try to get him to work far out..."

(Santiago) "He does not like to work too far out."

Then, a little bit further down:

(Manolin) "Are his eyes that bad?"

Here, what is "he/him/his" referring to? Is it referring to the boat, Santiago himself, or another person?

Thank you in advance,

Sean