"I do not imagine that this island is very large," said the captain, as he and Dave set out. "To my mind it won't be a bad idea to skirt the shore first."
"Just as you say," answered the youth.
"We want to keep our eyes peeled for the savages, though."
It was an easy matter to follow the shore on two sides of the island, but to the north and the west were numerous rocks, and they climbed over these only with the greatest difficulty.
"Be careful, or you'll sprain an ankle," said the captain.
"There seems to be a hill near the center of the island," said the young diver. "Wouldn't it be a good idea to climb to the top of that?"
"Yes, as soon as we have finished skirting the shore."
Presently they came to a spot where some extra high rocks hid what was beyond from their view.
"Hark!" cried Dave, coming to a sudden halt. "What was that?"
"I don't know," answered the captain. "Sounded like somebody calling, didn't it?"