In Jane Austen's day it was said that every family in Britain had a relative at sea.
Today the Merchant and Royal navies have shrunk and we live in an age of "sea blindness".
As the "Year of the Sea" begins, the nation has never been less realistically aware of her island status and of the curious, dislocated lives of her seafarers.
Libby Purves finds out how this challenging life has changed for those at sea today.
And how young people who have grown up in an individualistic culture where they can constantly question authority, learn to accept the discipline of life on board ship.