Her [Captain's girlfriend's] father had a strip of land on which he grew taro and bananas and he had a boat in which he went fishing. He was vaguely related to the mate of the schooner [Captain's schooner], and it was he who took Captain Butler up to the shabby little frame house to spend an idle evening. They took a bottle of whisky with them and the ukulele.
(W.S. Maugham; Honolulu)
Can we be at least 95% sure of whom 'he' refers to (the mate of the schooner or 'her father')?
I would think it was 'the mate of the schooner'.