An urgent call comes over the ship’s public address system. The "gators," the group of U.S. Navy spouses, children and relatives that boarded that morning, are ordered to muster immediately on the mess deck.
The voice rattles through the public address speakers again: "A man is in the water."
In the far corner of the mess deck, the gators gather around a few serious-looking sailors, including Cmdr. David McNutt. The civilians are spending their first day aboard the amphibious assault ship watching emergency response exercises and following their husbands, fathers, sons and boyfriends through the workday.
"Man still in the water, six minutes," the ship PA system warns.
A sailor steps to the center, holding a ship manifest. There will be a roll call.
Even out at sea, the first day of the tiger cruise is hot and balmy. The Essex MH-60S Knighthawk helicopters put on an flight demonstration, and the gator group stands on the flight deck sweating and snapping photos.
"Man still in the water, eight minutes."
Now, on the mess deck, gators fill up the tables, while some stand elbow to elbow. Some are giggling softly or just sitting quietly. Others glance around the deck nervously. Each raises a hand or calls back when their name is read from the manifest. The names come in alphabetical order. Smith, a sailor shouts.
"Man still in the water, 12 minutes."
The roll call is completed and each name is checked off the list. The sailors shuffle off, and the excitement is over. Everyone is safe.
The public affairs office says the drill — nobody went overboard — is the best way to ensure the safety of the 160 civilian guests on the tiger cruise.
Not even the crew knows whether such announcements are drills or real emergencies.
The gators are eating ice cream and battling it out over the "Guitar Hero" video game less than an hour later. Some may remember this trip for the rest of their lives.
Meanwhile, tonight, the passengers and crew of the USS Essex are present and accounted for and will sleep in safety.
The sound is not what you expect.
The gun’s report is more of a rapid buzz than a boom. It is sudden and brief and then a puff of white smoke.
"You don’t really hear bullets," says Jason Jahier, one of about 100 guests from the tiger cruise on the flight deck on the USS Essex for a weapons demonstration Friday.
In fact, the Phalanx Mark 15 Close-in Weapons System, a gray pod with a white arm mounted just off the Essex flight deck, resembles its computer-like name more than its distant cousins, the .50-caliber guns also used to protect the ship.
It is also far more lethal than the .50-calibers.
The "sea-whiz," as it’s called, fires a stream of 4,500 rounds per minute from a six-barrel Gatling gun.
Its infrared eye can draw a bead on anything with a heat signature whether it is a threatening airplane or a boat coming or going, said Chief Petty Officer Joshua Patat, who operates the Phalanx system.
The 20 mm tungsten rounds pierce metal, and during target practice, they shatter unmanned aerial drones, Patat says.
The Phalanx fires so many rounds so quickly that it can drain its ammunition drum in just 30 seconds.
The Navy cannot just fire a weapon like the Phalanx system into the horizon. Demos, like that for the tiger cruise, require a "huge evolution" to ensure safety. A hit or near hit to a passing ship could quickly become an international incident.
On deck, the tiger cruise guests wait and watch the Phalanx while behind the scenes several departments — operations specialists, the firing crew, ship-board weapons coordinators — work to ensure the sea is clear of potential innocent targets.
First, there’s a visual check by sailors with binoculars. Then ship radars scan the sea surface.
"Depending on congestion or area of operation, it could take a long time," Patat says.
Finally, after two to three surface tracks Friday, the crew is certain it has the required 12,000 yards of clear surface area, and the Essex commanding officer gives the go ahead to fire the Phalanx system.
"It was definitely startling," Jahier says.
The gun moves into position with a robotic jerk, pauses and without warning rips through several hundred rounds. Suddenly, the demo is over.