What does "jump ship" mean?

[ngoc_lan]

I don't understand the words "jump ship". Can you explain it to me?

"In 1841 Melville went to the South Seas on a whaling ship, were he gained the information about whaling that he later used in Moby-Dick. After jumping ship in the Marquesa Islands, he and a friend were captured by some of the islanders"
(Herman Melville, American Study Collection in American Resource Center)

I hope you will explain it so that I can know more about English. Thank you!

[5jj]

Definition of jump-ship | Collins English Dictionary

[ngoc_lan]

So it means: he left the ship legally or illegally?

[Gillnetter]

So it means: he left the ship legally or illegally?

He had a legal responsibility to stay on the ship. His leaving the ship was illegal.

[BobK]

He had a legal responsibility to stay on the ship. His leaving the ship was illegal.

But I don't think it's a good idea to get hung up on this 'illegality' thing. There were rules (enforced by someone), and deserting the ship was in breach of those rules.

b

[Barb_D]

Just to add: It's also used figuratively, to mean you leave a project or company abruptly, perhaps to save yourself or go on to something better, and leave the rest of the people involved to manage without you.

[BobK]

And the idea of 'the ship' as being a company or enterprise is also present in the expression 'go down with the ship': 'As Captain he was expected to go down with his ship''.

The same image underlies the idea of people 'leaving a sinkling ship'. Sometimes the idea is not explicit, but is implied by calling such people 'rats'. (I wouldn't swear to it, but it seems to me that could be the source of the expression 'to rat on someone'.)

b