What might Jim consider appropriate or prophetic about the song the drunken pirates are singing?

Jim believed that the song the pirates were singing was far too close to what the crew had been experiencing.... it reflected what had happened that very morning.

"But one man of her crew alive, What put to sea with seventy-five."

And I thought it was a ditty rather too dolefully appropriate for a company that had met such cruel losses in the morning. But, indeed, from what I saw, all these buccaneers were as callous as the sea they sailed on.