Initially rotating the scope's field of vision up to almost directly overhead, he slowly lowered it as the diving officer shouted out the decreasing depth. A few brightly colored tropical fish flashed in and out of his field of vision. Other than that, all he saw was the deep blue of open water.
As the scope broke the surface, Stuart lowered the field of vision until he felt the slight click of the handle detent, telling him he was looking straight out at the horizon. He had not seen any telltale shadow that would foretell an underwater collision. After a quick sweep around, he reported, "No close contacts." Another, more careful search and he reported to Hunter, "Completed initial search, no contacts."
Hunter acknowledged the good news and ordered, "Very well. Make your depth eight-zero feet."
Stuart brought the sub down to eighty feet. The slow, delicate procedure to turn a warship designed to fly effortlessly through the depths into a rock solid launch pad for the SEALs began.
Zero velocity, both horizontally and vertically, was essential. The force of any water flowing past the hatch would tear a SEAL out of the sub as he emerged or exhaust him as he tried to keep up with the moving ship. To make matters worse, the escape hatch on SAN FRANCISCO opened forward so that it had to be held open against the flow of water for any forward motion. Too much speed could slam the one ton steel hatch shut on any SEAL unfortunate enough to be emerging just then.
Any vertical motion would result in pressure changes too rapid for the SEALs to equalize. At best they would have ruptured eardrums, at worst, the terrible pain of an embolism.
Forward motion had to be maintained at less than a tenth of a knot while vertical motion had to be kept at less than a foot per second. Depth had to be maintained in a six-inch band. This required an inherent sense of anticipation of the forces acting on the great ship and an uncanny talent to counter them precisely. Chief Jones was truly unique in his ability to, almost unconsciously, integrate the input from the ship’s sensors with his own “seat of the pants” feel for the ship’s response. Flood a few pounds of water into one trim tank; pump a few pounds out of another. Watch the water temperature and depth gages with an eagle eye. Listen to the reports of ship’s velocity in the X, Y and Z-axis. And maintain very careful track of the vital lockout evolution happening thirty feet aft and a deck below his location. Doing all this instantaneously, precisely and for a four-hour period was not something that anyone could be trained to do. It required the one individual in a million who was born with these unique talents.
“All right, Chief. We are at eighty feet. I’ll slow to two knots. You trim the ship,” Hunter said. They had learned through many hours of trial and error the tricks that made this impossible maneuver possible. One key trick was to slow down incrementally to a hover and to trim the ship very carefully at each speed.
As the sub slowed, the stern started to sink. The ship came to rest with a three-degree up angle.
“Damn, Skipper, we’re heavy aft. Pumping one thousand pounds from after trim to forward trim,” Chief Jones commented.
The angle gradually eased, but the ship had sunk several feet in the ensuing minutes.
“Pumping from Auxiliaries to sea, one thousand pounds.”
The descent slowed, then stopped.
“Depth nine-zero feet coming to eight-zero,” he reported, as he used the little remaining speed to plane back up to the ordered depth. She settled out at precisely eighty feet. “Skipper, I’m ready to go to one point five knots.”
Hunter ordered, “Maneuvering, make one point five knots.”
The EOOW in the maneuvering room acknowledged "Make one point five knots, aye."
The sub slowed to one point five knots. The tedious, yet delicate procedure was repeated. Feel the sub’s response. Pump a little, flood a little. Carefully correct the minor imbalances of weight. Then slow again. Repeat the procedure. Slow some more. Repeat; until finally speed was down to almost zero.
At these very low speeds, just the turning of the great bronze screw caused enough torque on the ship to disturb the delicate balance. As each blade tip passed through the low pressure near the surface on the top of its rotation and then bit in to the higher pressure water on its downward travel, it would push the stern down and to port. This resulted in the bow moving to starboard and up. The inevitable result was for the sub to broach.
“Lower the outboard and shift to remote,” Hunter ordered. “All Stop.”
He grabbed the 7MC microphone. “Maneuvering, Captain. When the shaft is stopped, put the main engines on the jack.”
The mains would be warmed and ready if they were suddenly needed, but for now the outboard and its small electric motor and tiny screw would be used in quick bursts to gently move the ship.
The first four SEALs entered the cramped dark space of the escape trunk and dogged the lower hatch shut. The space was so small they could not don their scuba tanks but, rather, had to place them under their feet and stretch the regulator hoses to breath.
Boats climbed a little higher in the trunk and spoke into the intercom, “Swimmers ready,
