They made rapid course now toward Yucatan. The course was very easy to follow, the sunken isthmus being an established fact.
Many beautiful sights were daily witnessed in the sea depths. Many strange specimens were secured.
But no incident of a thrilling sort occurred until one day they had arrived within a few miles of Cape Catoche, as Frank estimated by his measurement of distance.
“It should be in sight,” he declared, “if we were on the surface.”
“Why not rise and take a sight at it to make sure?” asked Wade.
“We can,” agreed Frank.
So he stepped into the pilot-house and touched the lever. The next moment the submarine boat was flying upward.
Up out of the briny deep she shot, but the moment she emerged a disappointment was in store.
They had expected to sight the rugged headland of Cape Catoche directly in front of them, but they were in the midst of an impenetrable fog.
No object could be seen ten yards away. It was a discouraging predicament.