Tony sank back with a sigh of relief.
"Whew, that was close!" he exclaimed. "I didn't see those rocks until we were right on top of them. If we'd ever struck one of them we would have been goners."
The Hardy boys believed him. Angry waves dashed against the base of the cliff. They would not have lived more than a few minutes if they had been wrecked in this place. They would have been battered to pieces against the rocks.
Suddenly, before them, they saw an opening in the side of the cliff. It was a long, narrow cove.
The entrance was like the neck of a bottle, widening as it led into the cliff, and it was overshadowed by jutting rocks. It had been quite invisible up to this time, and the boat had gone only a few yards further before it became invisible again, so well was the opening hidden by the rocks.
"Here's a find!" exclaimed Frank, in excitement. "Let's turn back and see where this goes to."
Tony swung the boat around and the craft slowly made its way back toward the hidden cove. Soon the opening in the cliff came into view again.
"It's just large enough for the boat to go through," said Tony. "Want me to try it?"
