Answer:
"But it was only after a long silence, when he said, in a hesitating voice, "I suppose you fellows remember I did once turn fresh-water sailor for a bit," that we knew we were fated before the ebb began to run, to hear about one of Marlow's inconclusive experiences."
Step-by-step explanation:
Flashback in literary terms refers to a time in a story where the narrative is taken to a point in time from the story. This is usually done to show past events to fill some crucial backstory.
From the excerpt given, a flashback is used to remind the second character how he changed careers for some time to become a freshwater sailor before fortune turned and they began to hear about Marlow's inconclusive experiences.