The poem
How distant, the departure of young men Down valleys, or watching The green shore past the salt-white cordage Rising and falling.
Cattlemen, or carpenters, or keen Simply to get away From married villages before morning, Melodeons play
On tiny decks past fraying cliffs of water Or late at night Sweet under the differently-swung stars, When the chance sight
Of a girl doing her laundry in the steerage Ramifies endlessly. This is being young, Assumption of the startled century
Like new store clothes, The huge decisions printed out by feet Inventing where they tread, The random windows conjuring a street.

We think this poem has a link with This Be the Verse. There is a definite idea of separation: This Be The Verse uses you instaed of we and How Distant is talking about things away from the position of the narrator. Are we barking mad?
I think this poem could be about men leaving to go to war! The line, "simply to get away", was an opinion of many men who went to war and they thought it would be an exciting new experience as many had never left thier home county. Larkin was also of this generation so may have experience of this. There is a definate sense of leaving things behind and passing of time and place.
This poem is all about the point between past present and the possible future. The use of 'ramified endlessly' shows of how the young girl could be his sister or mother.
Like many of Larkin's poems it also has a hint of age vs youth about it. although without the usual bitterness.
I thought that the poem was about the coming of age, and the young moving away from their villages to be with the other young people, and experience life.
i have a very big nose but unfortunetly i av a very small willey,why cudnt it be the other way round
Having read this poem i feel that is it about young people wanting to get away and explore for themselves.
The line 'Simply to get away From married villages before morning' means to me that he [the persona] wants to get away from the stifiling village where he was born. The idea of cattlemen makes my reasoning stronger for this.
The lines 'When the chance sight Of a girl doing her laundry in the steerage Ramifies endlessly' means to me the freedom of youth, in terms of feelings of a boy to a girl, sexually. Which he would not have been allowed to feel without guilt while he was stuck in his village.