How an Ancient Tool Led to Unexpected Collisions and Shaped Naval Procedure
Mention the word “submarine” to anyone, and a host of images spring to mind: the sleek, low black silhouette pier-side, the drama of an “emergency blow” as the boat broaches the surface in a volcanic eruption of water, and the sinister image of a periscope feathering the surface, hinting at what lurked below.
The periscope became the eye of the submarine. It was invented and developed solely for the purpose of providing a means to view the surface without fear of detection by surface craft.
When Submarines Came Up Under the Unexpected
Over the decades, submarines coming to periscope depth have occasionally hit objects on the surface, though such incidents were rare and typically harmless—at least for the submarine.
The Fishing Boat Incident, Philippines (Mid-1980s)
James Mowrey, a former US Navy Nuclear Submarine Officer, recalled a remarkable encounter from the Philippines in the mid-1980s. While serving in the Control Room during operations, his friend was the Officer of the Deck (OOD) as the submarine came to periscope depth on a beautiful day. As the scope broke the surface, there was a muffled “bong” sound followed by the OOD calling out in alarm and immediately ordering a rudder swing.
It turned out the scope had struck a small one-man fishing boat. From his low-power periscope view, the OOD watched the fisherman tumble overboard. The man swam back to his vessel, climbed aboard looking scared and very confused, and sailed off—never knowing what had hit his boat. As Mowrey noted, the fisherman “is still telling the story of ‘something’ hitting his boat, knocking him overboard, but then never appearing.”
The Cardboard Box Incident, Mediterranean (Early 1990s)
John Hartzog, another former US Navy Nuclear Submarine Officer, experienced an even more unusual encounter while on patrol in the central Mediterranean in the early 1990s. The submarine was coming to periscope depth on a calm, sunny summer day to obtain a satellite fix and receive radio traffic.
After the routine preparations and raising of the periscope, the Officer of the Deck began scanning the underside of the surface for “shapes and shadows”—a critical safety procedure. Just as the scope was breaking the surface, he yelled “emergency deep,” immediately putting the crew on high alert, as this command implies the submarine was about to collide with something. Sonar had detected nothing, but passive sonar had limitations—particularly against sailboats running silently without engines or generators.
After reaching a safe depth beneath even the deepest-drafted ships, the crew circled back and tried again. This time, they discovered the culprit: a cardboard box floating upside down. The periscope had come up inside it. As Hartzog reflected, “Not so much a needle in a haystack, more like threading a needle in a haystack.”
Why Raise the Periscope When Diving?
The procedures governing submarine operations developed out of hard-won lessons. David Kirk, a former US Navy Submarine Officer and Strike Warfare Officer, explained the multiple reasons the periscope was raised during a dive:
Visual Surveillance. The Officer of the Deck was required to continue scanning the horizon to ensure no enemy threat aircraft or surface ships detected them until they achieved submersion.
Ballast Tank Verification. The OOD needed to visually verify that the main ballast tank (MBT) vents had properly opened and were venting. If one failed, the tank would not properly fill with water, affecting reserve ballast and damage control capabilities. The OOD would announce “Venting Forward” and then report “Venting Aft” after looking to confirm the aft vents were functioning.
Deck Status Monitoring. By procedure, the OOD reported when “the decks were awash,” allowing the chief of the boat to close the MBT vents at the appropriate moment.
Scope Under Notification. When the scope went under, the entire ship’s control party needed to know, so the Chief of the Watch could lower any remaining masts or antennae. This also allowed the Diving Officer of the watch to use a larger down angle to proceed to depth without fear of the propeller breaking the surface.
Why Procedures Matter
Submariners lived and died by written procedures. Officers reviewed them before every operation, and crews treated them as checklists during every evolution. When a casualty occurred, sailors performed immediate actions and then consulted procedures to audit their response.
This obsession with procedure grew from tragedy. Between 1905 and 1935, approximately 20 submarines were sunk and subsequently raised pier-side. Early submarine crews, treating their boats like surface ships, relied on tribal knowledge and the “all-knowing” senior NCOs. Many submarines sank alongside their piers because simple steps were forgotten or overlooked. This tragic history led to the submarine warfare patch, later the submarine warfare pin, which was developed to identify sailors who faced the added risks of submarine service. This formal program eventually influenced the aviator, special warfare, and even the surface warfare communities.
According to Kirk, “If in the middle of doing an evolution you determine the procedure is flawed, you place the ship or the reactor into a safe condition, stop the procedure, go back to the appropriate officers and chiefs to rewrite it, then train on it, and then attempt it again.”
Procedures did not replace common sense or intuition; they enhanced both by ensuring no critical step was overlooked. The duty officers—the Officer of the Deck, the Engineering Officer of the Watch, and other watch-standers—served as the final safeguards to ensure procedures were followed and contradictions did not result in damage or loss of life.
In the underwater realm where margins for error were nonexistent, procedures were not merely suggestions—they were survival itself.
Photos by Photographer’s Mate 1st Class Kevin H. Tierney / U.S. Navy
