In Twenty Thousand Leagues Under the Sea, Ned’s plan of escape once the Nautilus had entered the Mediterranean sea was to use the lifeboat to facilitate his escape with Conseil and Aronnax. They planned to escape while the captain was still in bed.
The plan was that Ned would be at the central companionway, together with Conseil, while Aronnax would wait in hiding somewhere in the library and only move when Ned gave the signal. Every step was planned extensively.
While implementing his plan, Ned found and held onto a monkey wrench, hoping that it would prove effective in loosening the nuts that were used to bolt down the lifeboat. Ned was counting on his knowledge of how to operate the lifeboat to the Nautilus. All of this was anticipated as a way for them to reach the surface of the Mediterranean without drawing anyone’s attention to their suspicious behaviour.