'16 October 1829: the Doctor and Benny book passage aboard the passenger ship Mermaid out of Sydney, but show up late, delaying the vessel's departure. Perhaps due to the delay, the ship runs into a storm four days later that damages and sinks the vessel. The Doctor and Benny ensure that everyone evacuates safely, and three days later, the survivors are picked up by another ship, the Swiftsure. However, on the 28th, the Swiftsure runs into an unexpected current and is dashed against the rocks. Once again, the Doctor and Benny are instrumental in saving everyone's lives, and later that day, the survivors are picked up by the Governor Ready... which burns to the waterline two and a half hours later. However, Benny spotted the Doctor slipping into the cargo hold shortly before the fire broke out, and she realises that the Doctor has been sinking the ships deliberately. When the survivors are picked up by the Comet, the Doctor asks Benny to apply an acid to the ship's mast so it will snap during the next storm, assuring her that this is vital to the integrity of the Web of Time. Benny reluctantly does so, and on 3 November, the mast snaps during a storm and the ship sinks. By now, even though nobody has actually died, the crew of the Mermaid are considered to be jinxed; however, the Doctor and Benny intervene to ensure that the tensions do not lead to violence. Finally, in the early hours of 4 November, the many survivors are picked up by the Jupiter, a passenger liner en route for Sydney. Aboard the Jupiter is a dying woman named Sarah Richley, whose son, Peter, was a crewman aboard the Mermaid. She would have died without ever being reunited with her son, but when they meet aboard the Jupiter, their joyful reunion give her the strength to fight off her illness. She will survive for years to come. The Doctor admits to Benny that he owed Sarah a favour, but when Benny asks him why he didn't just transport Sarah directly to Sydney in the TARDIS rather than going to all this trouble, she is rather peeved to realise that it hadn't occurred to him to do so.'
[The Doctor in question is the Seventh Doctor. 'Benny' is Bernice Summerfield.]
Source: drwhoguide.com (http://www.drwhoguide.com/whotrip9.htm). Sighted 19/5/11