Submerging again, Tom steered closer and swept the underwater formation with the yellow glare of their beam. “It’s a guyot, Bud!”
“A ghee-oh? What’s that?”
“A flat-topped, extinct underwater volcano,” Tom explained.
“Oceanographers have spotted a number of them in both the Atlantic and Pacific.
They were named after a Princeton professor.”
“What gave ‘em that flat Ivy League crew cut?”
Tom grinned. “One guess is, they stood above sea level centuries ago and were worn down by the surf.”
Tom landed the Sea Hound atop the undersea mesa. Then he and Bud donned hydrolung gear and went out through the ship’s air lock. The boys separated to look around.
The edges of the guyot were fringed with a natural deposit of large stones.
Bud realized he and Tom had been too far away and at too low a depth for a clear view of the mesa top when they sighted it before. Suddenly his earphones crackled with an excited call from Tom:
“We weren’t imagining things, Bud-something was going on here! I’ve just found a clue!”
CHAPTER X
BLOODHOUND EXPERIMENT
BUD glided quickly to his friend’s side. Tom was holding up a portable underwater lantern!
“One of the lights we saw!” Bud exclaimed. “There must have been divers operating herel”
“Right,” Tom agreed. “And whatever they were doing must’ve been important or that electric trawler wouldn’t have been guarding the spot.”
Back on the Sea Hound, Tom examined his find.
“A mercury short-arc lamp with a cadmium battery. Boy, this is really powerful, Bud I”
“Ever seen one like it before?” Bud asked.