1800:- Young Edmund Talbot is sailing to Australia to take up a government post, on a decrepit old ship skippered by Captain Anderson, who is hostile to Edmund until he realizes that he has important relatives. Far more admirable to Edmund are Lieutenants Summer, who has worked his way up through the ranks, and the dashing Deverel. His fellow passengers number demure governess Miss Granham, the republican Mr Prettiman and artist Mr Brocklebank, travelling with his wife and daughter Zenobia - who initiates Edmund into sex - though ultimately he realizes that they are not related, merely a carnal ménage a trois. Also on board is the gauche young vicar Colley, who inadvertently breaches protocol by going onto the bridge uninvited. Ashamed he gets drunk and has gay sex with crew members before locking himself in his cabin, where, despite Edmund's efforts to bring about reconciliation, he wastes away and dies.

The ship is becalmed and another vessel is sighted, which turns out to be British - the Alcyone, whose commander announces that the war with France is over. The two vessels anchor alongside and a ball is held for the passengers. Here Edmund meets the sweet Marion Chumley, though he has a rival for affections in Deverel. However, when the two ships part Deverel is exchanged for the Alcyone's officer, the urbane Benet and Edmund confides in Summers his regret at having to say goodbye to Marion. A storm blows up, during which the unfortunate steward Wheeler, considered a Jonah, is thrown overboard and Prettiman severely injured, being nursed rather unexpectedly by Miss Grnham. A mast is also broken and Benet and Summers disagree over the best way to mend it.

Edmund acts as a witness to the wedding between the injured Prettiman and Miss Granham, with flowers grown by the captain in his window boxes. Despite initial animosity towards him Edmund starts to show some admiration for the older man's liberal ideas. With the mast broken the ship is drifting perilously close to an ice-field but Benet saves the situation by pouring molten lead into the mast's base, which steadies it and the ship reaches Sydney safely. Due to Edmund's influence Summers is given his own ship but dies when it catches fire though for Edmund there is a happy ending as he is reconciled with Marion, who has also arrived in Sydney.