In a few minutes the Skipper went out and ordered the sub up to periscope depth, had the ’scope run up and took a look around.

“Not a thing in sight,” he announced. “Down ’scope.”

As the big shaft slid down into its well in the deck, the Skipper ordered the ship to surface once again, and up she came. Gray was the first man up on the bridge, and the other officers quickly followed him. Lookouts and controlmen took their posts, and the Kamongo went steadily ahead on her course.

Corvin took over the watch on the bridge and in a little while the others went below. The crew had settled down and once more everything was serene and quiet.

More days went by, but without the excitement of even a sight of ship or plane. After they had passed into the Caribbean Sea, the Skipper ordered them to hold up for two hours before proceeding.

“We’re a bit ahead of schedule,” he explained, “because of the extra speed we made on the surface. Coming into Panama, we’ve got to surface and run exactly on schedule and on course. Patrol craft and planes are expecting us and they’ll bomb us out of sight if we’re five minutes off schedule or two degrees off course.”

When they resumed speed, on the surface, March checked the boat’s position regularly to make sure of their course. The first time a big Martin PBM-1 shot out of a cloud ahead of them, March felt his throat grow dry. If they were not exactly where they should be at that moment, he knew what would happen to a beautiful new sub and about sixty-four good men of Uncle Sam’s Navy.

But the patrol plane just circled low overhead, gunned its motors and flew away. He knew that its radio reported the sub’s position to other patrol craft, and that they would be checked up on regularly.

Two other planes came over for a look on their way in toward the Canal, and for the last twenty-five miles they were sighted by half a dozen surface ships.

“Are we to go right on through without stopping?” March asked the Skipper.