The partitions had doors that were shut hermetically by means of india-rubber instruments, and they ensured the safety of the Nautilus in case of a leak.
I followed Captain Nemo through the waist, and arrived at the centre of the boat.

There was a sort of well that opened between two partitions.
An iron ladder, fastened with an iron hook to the partition, led to the upper end.

I asked the Captain what the ladder was used for.
"It leads to the small boat," he said.
"What! have you a boat ?" I exclaimed, in surprise.
"Of course; an excellent vessel, light and insubmersible, that serves either as a fishing or as a pleasure boat." "But then, when you wish to embark, you are obliged to come to the surface of the water ?" "Not at all.

This boat is attached to the upper part of the hull of the Nautilus, and occupies a cavity made for it.

It is decked, quite water-tight, and held together by solid bolts.