# XIII explained — The Coral Island

> Chapter companion for The Coral Island by R. M. Ballantyne.

## What happens

Jack, Ralph, and Peterkin investigate a mysterious green light near the waterspouts. Jack dives into the sea to explore and discovers it is a stream of light from a submarine cave. After a prolonged absence that causes panic, he resurfaces safely. They later return with a torch and explore the cave, which they name the Diamond Cave, finding it filled with coral formations and sparkling walls.

## Themes in this chapter

### Adventure and Exploration

The boys investigate a mysterious green light and discover a submarine cave, highlighting their adventurous spirit.

### Nature and the Sublime

The Diamond Cave's awe-inspiring coral formations and sparkling walls evoke the sublime beauty of nature.

### Friendship and Loyalty

Peterkin's intense fear and relief at Jack's safety underscore the deep bond among the boys.

## Character check-ins

### Ralph Rover

Narrator; participates in the exploration of the submarine cave.

### Jack Martin

Dives to investigate the green light, discovers the Diamond Cave, and leads the exploration.

### Peterkin Gay

Initially anxious and fearful when Jack is underwater; later jokes about the adventure.

## Key lines

> Come, Jack, let's be jolly today, and do something vigorous. I'm quite tired of hammering and hammering, hewing and screwing, cutting and butting, at that little boat of ours, that seems as hard to build as Noah's ark; let us go on an excursion to the mountain top, or have a hunt after the wild ducks, or make a dash at the pigs.

Peterkin urges Jack to take a break from boat-building and go on an adventure.

_Peterkin expresses boredom with construction work and a desire for excitement._

> Now, lads, yon green object is not a shark; it is a stream of light issuing from a cave in the rocks.

Jack explains that the mysterious green light is sunlight reflecting from an underwater cave.

_Jack reveals the discovery of the submarine cave after his dive._

> The roof of the cavern just above us seemed to be about ten feet high, but grew higher as it receded into the distance, until it was lost in darkness. It seemed to be made of coral, and was supported by massive columns of the same material.

The cave's ceiling is low near the entrance but rises deeper in, with coral columns resembling those in a cathedral.

_Description of the Diamond Cave's interior, emphasizing its grandeur._

## Links

- HTML: https://www.betterreads.online/discover/the_coral_island_se/chapters/xiii
- Book: https://www.betterreads.online/discover/the_coral_island_se
- All chapters: https://www.betterreads.online/discover/the_coral_island_se/chapters