He was so suprised that he inhaled sharply.
Those were the only kind of ship that he knew.
This topic is the invasion of America by the Spaniards. The words that refer to this invasion are: 'nothing' to show the dramatic change, 'magic' which potrays that the Native American man did not know how they appeared so suddenly, 'bellying' shows how the sails bulged in the wind, and the alliteration in 'clambering crews' shows how the sailers were working hard and noisily on board the ships to manage the sailing.
He uses this line to emphasize how many sailors there were against a solitary man. This vulnerability is further emphasized by using the word 'naked' to show that he was unprotected and naive.
"clambering crews"