g on an idea.

The chicken had dropped pretty close to them. But since their floats
were tied to the reef, and their bubbles were carried off a vertical
path by the light currents, neither could have been used to pinpoint
their whereabouts--_unless whoever dropped the chicken had an excellent
knowledge of the currents in this particular place_!

He carried the thought further. The shadow had gotten upset because he
and Scotty had gone swimming in an area where something was hidden. At
least, that was a reasonable assumption, based on the events at St.
Thomas. The fancy diving gear in the house, the attempt to warn them
off, and the presence of Steve's erstwhile shadow on Clipper Cay could
then be added up.

Right here, in this particular area, another mysterious something was
hidden! Something that the fancy frogmen dived often to see, use,
collect, or whatever they did with it. That would account for their
familiarity with the currents!

He started to tell Tony, then reconsidered. It was a pretty good
hypothesis, he thought, but not supported by ironclad evidence. If he
told the scientists, they might forbid any more diving in the area. And
he was determined to get that treasure--more for his sister Barby than
for himself. If he failed to get it there would be no living with Barby,
since she would always maintain _she_ could have found it if they had
only allowed her to go on their old expedition.

Zircon and Scotty broke water and Rick helped them aboard.

"It's a ship, and a sailing ship at that," Zircon boomed. "We identified
what was almost certainly a compass binnacle, probably brass, but there
wasn't time to get it free and bring it up. Scotty found what is
probably the muzzle of a cannon, buried in the sand."

"There's so much growth over everything that it's hard to tell what's
what," Scotty added. "But it certainly looked like a cannon muzzle."

"From what we saw, I suspect that the portion above the sand is the
stern, probably the stern super-structure. If the timbers haven't
completely rotted away, ripping off the top should expose the stern
cabins."

"That seems reasonable," Tony agreed. "At any rate, it's a good basis
for operation. Rick, if you'll look in my kit, you will find a larger
bar you can borrow. You'll both need tools if you're going to take the
ship apart."

"Anyway, that's enough diving for the morning," Zircon said. "Let's up
anchor and go."

While the others got the boat underw