  &nbsp;I believe that the Thames river, more that just part of the scenery, is a symbol of the beginning of great adventures or challenges. Many famous persons had commenced their journeys here, one of them Sir Frances Drake on "the Golden Hind", or Sir John Franklin. I think that the author is saying that, as those famous adventurers,&nbsp;the protagonists&nbsp;who will be part of the story are also in the Thames river, going for their own journey ahead. With the river's description, Conrad introduces the reader to the story, and prepares him for what is coming. 
