In Chapter 6, Ralph and Jack stand looking at the sea. What does this episode demonstrate about Ralph?
here's the quote from the book: "The lagoon had protected them from the Pacific: and for some reason only Jack had gone right down to the water on the other side. Now he saw the landsman's view of the swell and it seemed like the breathing of some stupendous creature. Slowly the water sank among the rocks, revealing pink tables of granite, strange growths of coral, polyp, and weed. Down, down, the waters went, whispering like the wind among the heads of the forest. There was one flat rock there, spread like a table, and the waters sucking down on the four weedy sides made them like cliffs. Then the sleeping leviathan breathed out - the waters rose, the weed streamed, and the water boiled over the table rock with a roar. There was no sense of the passage of waves; only this minute-long fall and rise and fall. " but i'm not quite sure if it's the right section? but i am pretty sure it is correct. seeing as it mentions the sea and is said by ralph.
At the point you mention, Ralph is realizing the power of the tide and the fact that time and space and motivation have positioned the boys far enough away from the fire that it is sure to become a lesser priority if they choose to go and explore this new found island now. In Jack's mind this appears a great military stronghold and worth exploration at this exact moment.
This diversion of purpose between the two of them demonstrates a valuable lesson: Ralph is maturing in leadership, while Jack is longing for leadership but digressing in his quality to be a leader. Ralph has chosen correct priorities and because this time occurs and Ralph and Jack's ideas are juxtaposed against each other, we see Ralph grow. This growth is the most important association to take away from the episode.