They were now skirting the edge of a huge green-clad mushroom of coral, and Franklin peered into the shadows beneath it. There were a few large boulders there, and a pair of elegant angelfish which almost disappeared when they turned edge on to him. But he could see nothing else to justify Burley's interest.
It was very unsettling when one of the boulders began to move, fortunately not in his direction. The biggest fish he had ever seen-it was almost as long as the torpedo, and very much fatter-was staring at him with great bulbous eyes. Suddenly it opened its mouth in a menacing yawn, and Franklin felt like Jonah at the big moment of his career. He had a glimpse of huge, blubbery lips enclosing surprisingly tiny teeth; then the great jaws snapped shut again and he could almost feel the rush of displaced water.
Don seemed delighted at the encounter, which had obviously brought back memories of his own days as a trainee here.
"Well, it's nice to see old Slobberchops again! Isn't he a beauty? Seven hundred and fifty pounds if he's an ounce. We've been able to identify him on photos taken as far back as eighty years ago, and he wasn't much smaller then. It's a wonder he escaped the spear fishers before this area was made a reservation."
"I should think," said Franklin, "that it was a wonder the spear fishers escaped him."
"Oh, he's not really dangerous. Groupers only swallow things they can get down whole-those silly little teeth aren't much good for biting. And a full-sized man would be a trifle too much for him. Give him another century for that."
They left the giant grouper still patrolling the entrance to its cave, and continued on along the edge of the reef. For the next ten minutes they saw nothing of interest except a large ray, which was lying on the bottom and took off with an agitated flapping of its wings as soon as they approached. As it flew away into the distance, it seemed an uncannily accurate replica of the big delta-winged aircraft which had ruled the air for a short while, sixty or seventy years ago. It was strange, thought Franklin, how Nature had anticipated so many of man's inventions-for example, the precise shape of the vehicle on which he was riding, and even the jet principle by which it was propelled.
"I'm going to circle right around the reef," said Don. "It will take us about forty minutes to get home. Are you feeling O.K.?"
"I'm fine."
"No ear trouble?"
"My left ear bothered me a bit at first, but it seems to have popped now."
"Right-let's go. Follow just above and behind me, so I can see you in my rearview mirror. I was always afraid of running into you when you were on my right."
In the new formation, they sped on toward the east at a steady ten knots, following the irregular line of the reef. Don was well satisfied with the trip; Franklin had seemed perfectly at home under water-though one could never be sure of this until one had seen how he faced an emergency. That would be part of the next lesson; Franklin did not know it yet, but an emergency had been arranged.
