That afternoon the sea appeared to be strangely agitated, and toward night the sailors noticed a large number of dead fish rising to the surface. Dave discovered a large shark, and this proved to be dead, also.
"There has been some disturbance under the ocean's surface," said Captain Marshall. "More than likely an earthquake."
"An earthquake! And we never knew it!" ejaculated Roger, and his tone showed his disappointment.
In the morning the sea was more agitated than ever. One minute it would appear to flatten out, the next, two waves would come together with a clash that sent the spray flying upward for many feet. More dead fish were in evidence on every hand.
"I have never witnessed anything like this," commented Captain Marshall. "I trust it gets no worse."
When the breeze sprang up, it came from the wrong direction, and the Stormy Petrel had to tack as best she could. The breeze kept growing stiffer and stiffer, until it was little short of a gale. Then a thick mist settled down on the ocean, shutting out the view upon all sides.
"I must say I don't like this," observed the senator's son. "Supposing we should run into something?"
"There isn't much to run into," replied Dave. "I just asked the captain, and he told me we were a good many miles from land of any sort."
"We might run into some other ship."
"There seem to be very few ships in this locality."