The Loss and Rediscovery of USS F-1: Lessons from a Century-Old Tragedy
Professional Maritime Archaeology Reveals New Details of 1917 Submarine Collision
By Naval Proceedings Staff
On 17 December 1917, eight days before Christmas, the nascent U.S. submarine force suffered one of its most devastating peacetime losses when USS F-1 (SS-20) sank in 10 seconds following a collision with her sister ship USS F-3 (SS-22) during routine training exercises off San Diego. The tragic incident, which claimed 19 of 24 crew members, stands as a stark reminder of the inherent dangers of submarine operations and the critical importance of surface navigation protocols—lessons that remain relevant to today's submarine force.
Recent advances in deep-ocean technology have now provided unprecedented insight into this century-old maritime disaster. In February and March 2025, an interagency team led by the Woods Hole Oceanographic Institution (WHOI), working in conjunction with the Office of Naval Research, Naval History and Heritage Command, and the National Science Foundation, conducted the first comprehensive survey of the F-1 wreck site using cutting-edge submersible and autonomous underwater vehicle technology.
Historical Context and Operational Background
The F-class submarines represented America's early commitment to undersea warfare capability. USS F-1, commissioned in 1912, was conducting a 48-hour engineering performance test as part of routine fleet exercises when the fatal collision occurred. The submarine was participating in surface maneuvers with USS F-2 and USS F-3 in waters approximately 4.5 nautical miles southwest of La Jolla, California.
Contemporary accounts indicate that deteriorating weather conditions, including dense fog, significantly impacted visibility during the exercise. Radio communications between the three submarines were reportedly compromised, and the vessels were operating at surface speeds when F-3's bow struck F-1's port side with devastating effect. Survivors described the damage as resembling "a big ax" strike that breached the engine room and port ballast tanks.
The rapidity of F-1's sinking—estimated at 10 seconds—underscores the catastrophic nature of the hull breach. Only five crew members were rescued by F-3, which remained on station to conduct search and rescue operations despite her own structural damage. The loss highlighted critical deficiencies in early submarine surface navigation procedures and inter-vessel communication protocols during formation operations.
The 2025 Scientific Expedition
The recent expedition marks a significant advancement in underwater archaeological methodology and naval heritage preservation. Utilizing the human-occupied vehicle (HOV) Alvin and the autonomous underwater vehicle (AUV) Sentry, the research team conducted seven dives to depths exceeding 1,300 feet—well beyond the operational limits of conventional diving operations.
The expedition's technical achievements include:
Advanced Sonar Mapping: Sentry's high-resolution sonar systems generated detailed bathymetric maps of the wreck site and surrounding seafloor, providing precise positioning data for archaeological documentation.
Photogrammetric Reconstruction: High-definition imagery captured during the dives enabled specialists to create comprehensive 3D models of the submarine's current condition, facilitating detailed structural analysis without physical disturbance of the wreck site.
Biological Survey: The team documented marine life that has colonized the wreck over the past 107 years, providing valuable data on deep-ocean ecosystem development around artificial reef structures.
"Once we identified the wreck and determined it was safe to dive, we were able to capture never-before-seen perspectives of the sub," reported Bruce Strickrott, WHOI senior pilot and expedition leader. The precision of modern deep-submergence technology allowed for detailed examination of hull damage that was previously documented only through limited sonar contacts.
Archaeological Findings and Structural Analysis
The submarine's remarkably intact condition surprised researchers, with the hull showing minimal deterioration despite more than a century on the ocean floor. The cold, oxygen-poor environment at depth has effectively preserved much of the vessel's structure, allowing for detailed analysis of the collision damage.
The photogrammetric reconstruction clearly shows the catastrophic breach on F-1's port side, confirming historical accounts of the collision's severity. The damage pattern indicates that F-3's bow struck F-1 at a significant angle, penetrating the pressure hull and allowing rapid flooding of multiple compartments.
Underwater archaeologist Brad Krueger, who participated in the dives, emphasized the expedition's dual purpose of scientific investigation and memorial commemoration. "History and archaeology are all about people," Krueger noted. "We felt it was important to read their names aloud"—referring to the 19 crew members who perished in the sinking.
Operational Lessons and Modern Relevance
The F-1 tragedy offers several enduring lessons for contemporary naval operations:
Communications Protocol: The breakdown in radio communications between the three submarines during the exercise highlights the critical importance of robust communication procedures during formation operations. Modern submarine forces benefit from significantly advanced communication systems, but the fundamental requirement for clear, redundant communication channels remains paramount.
Surface Navigation Procedures: Operating multiple submarines in close proximity on the surface, particularly in reduced visibility conditions, requires precisely executed navigation protocols. Current submarine doctrine incorporates lessons learned from incidents like the F-1 collision in establishing safe separation distances and approach procedures.
Weather Assessment: The decision to continue exercises in deteriorating weather conditions reflects the challenge naval commanders face in balancing training requirements with operational safety. Modern weather forecasting and sea-state assessment capabilities provide submarine commanders with significantly enhanced situational awareness.
Emergency Response: F-3's immediate response to the collision, remaining on station to conduct search and rescue operations despite her own damage, exemplifies the naval tradition of mutual assistance and demonstrates the importance of pre-planned emergency procedures.
Heritage Preservation and Naval Tradition
The 2025 expedition serves not only scientific and historical purposes but also fulfills the Navy's commitment to honoring fallen shipmates. Following completion of the diving operations, the research team conducted a formal remembrance ceremony aboard R/V Atlantis, ringing the ship's bell 19 times in memory of the lost crew members.
"As a Navy veteran, making this dive—together with another Navy veteran and a Navy historian—was a solemn privilege," observed Office of Naval Research Program Officer Rob Sparrock, who participated in the submersible operations. This sentiment reflects the deep connection between past and present naval service members and the importance of preserving maritime heritage.
Implications for Future Operations
The technological capabilities demonstrated during the F-1 expedition have significant implications for naval archaeology and heritage preservation. The integration of HOV and AUV platforms provides a powerful tool set for documenting historically significant wrecks while maintaining the integrity of these underwater grave sites.
Naval History and Heritage Command Director Rear Admiral (Retired) Sam J. Cox emphasized the contemporary relevance of historical incidents: "Operating at sea has always been inherently dangerous, and even more so for early submarines. In this case, night, fog, speed, and radio miscommunications contributed to the loss of 19 men, who demonstrated great courage just by volunteering for submarine duty in those days."
DEEP SUBMERGENCE TECHNOLOGY: THE 2025 USS F-1 EXPEDITION
The 2025 expedition to document USS F-1 represented a convergence of three cutting-edge underwater platforms operated by the National Deep Submergence Facility (NDSF), demonstrating the current state-of-the-art in deep-ocean archaeological research.
Research Vessel Atlantis (AGOR-25) Primary Platform and Command Center
- Class: Thomas G. Thompson-class oceanographic research vessel
- Length: 274 feet (83.5 meters)
- Displacement: 3,510 long tons
- Crew Capacity: 36 crew members plus 24 scientific personnel
- Endurance: 60 days at sea, 32,000 kilometer range
- Propulsion: Twin-screw diesel-electric, 11.0 knot cruise speed
- Construction: Delivered to U.S. Navy April 1997, operated by WHOI
Key Capabilities:
- Six dedicated science laboratories totaling 3,500 square feet
- Three winches and three cranes specifically designed for submersible operations
- Precision navigation systems with differential GPS
- Multibeam sonar mapping systems for bathymetric surveys
- Satellite communications enabling real-time data transmission
- Specialized launch and recovery system (LARS) for Alvin operations
Human Occupied Vehicle (HOV) Alvin Manned Deep-Submergence Platform
- Maximum Operating Depth: 6,500 meters (21,325 feet) - recent upgrade from 4,500m
- Dimensions: 7.0m length × 2.6m beam × 3.6m height
- Weight: 20 metric tons (40,000 pounds)
- Personnel Sphere: 4.8 cubic meters titanium sphere
- Crew Complement: 1 pilot + 2 scientific observers
- Dive Duration: 6-10 hours per mission
- Propulsion: Six reversible thrusters providing omnidirectional maneuverability
- Power: Dual banks of lead-acid batteries (120V, 140 AH each)
Scientific Equipment:
- Five viewports: three forward (17" diameter), two side (12" diameter)
- Two robotic manipulator arms for sample collection and instrument deployment
- Science basket payload capacity: 181.4 kilograms (400 pounds)
- High-definition still and video camera systems
- LED lighting array for deep-ocean illumination
- Precision navigation using inertial systems and acoustic positioning
Autonomous Underwater Vehicle (AUV) Sentry Unmanned Survey and Reconnaissance Platform
- Maximum Operating Depth: 6,000 meters (19,685 feet)
- Dimensions: 9.5 feet long × 7.2 feet wide × 6 feet high
- Configuration: Hydrodynamic wing design enabling "flight" over rough terrain
- Endurance: 100 km range at 2.5 knots, 150 km at 1.5 knots
- Power: 1,000 lithium-ion batteries specially adapted for high-pressure environments
- Navigation: Doppler velocity log, inertial navigation system, acoustic positioning (USBL/LBL)
Sensor Suite:
- EM2040 Multibeam Sonar: High-resolution bathymetric mapping capability
- Sub-bottom Profiler: Penetrates seabed for geological structure analysis
- Sidescan Sonar: Provides acoustic imagery of seafloor features
- High-resolution Digital Camera: Capable of photographing every 3 seconds for 60 hours
- Dual High-power Strobes: 5-10 times more powerful than studio lighting
- Magnetic Sensors: Detects ferrous objects and geological features
- CTD Sensors: Measures conductivity, temperature, and depth
Advanced Sonar Mapping Technology
The expedition utilized state-of-the-art multibeam echo sounder (MBES) technology, which represents a significant advancement over traditional single-beam sonar systems. Multibeam sonars emit multiple acoustic beams simultaneously across a wide swath, enabling comprehensive seafloor mapping with centimeter-level resolution.
Technical Capabilities:
- Beam Configuration: Multiple acoustic beams fired simultaneously
- Frequency Range: Typically 200-400 kHz for high-resolution applications
- Swath Coverage: Up to 5-7 times water depth in optimal conditions
- Resolution: Sub-meter bathymetric accuracy at operational depths
- Data Processing: Real-time beam forming and bottom detection algorithms
Photogrammetric Reconstruction Process
The creation of precise 3D models from the collected imagery required sophisticated photogrammetric processing techniques:
Data Collection Protocol:
- Systematic high-definition photography from multiple angles and distances
- Overlapping image sequences ensuring complete coverage
- Precise navigation data integration for georeferencing
- Calibrated lighting conditions using standardized strobes
Processing Methodology:
- Structure from Motion (SfM): Automated feature matching across image sequences
- Bundle Adjustment: Simultaneous optimization of camera positions and 3D points
- Dense Point Cloud Generation: Creation of millions of precisely positioned 3D points
- Mesh Generation: Surface reconstruction using Poisson or Ball Pivoting algorithms
- Texture Mapping: Application of photographic detail to 3D geometry
Scientific Output: The photogrammetric models provide unprecedented documentation capabilities, enabling precise measurements of structural damage, marine growth assessment, and long-term condition monitoring without physical disturbance of the archaeological site.
Expedition Operations Matrix
- Total Dives Conducted: Seven comprehensive survey missions
- Operational Dates: February 24 - March 4, 2025
- Survey Area: Comprehensive mapping of 1,300+ foot depth wreck site
- Data Products: High-resolution bathymetric maps, photogrammetric 3D models, HD video documentation
- Archaeological Documentation: First comprehensive survey since wreck discovery in 1975
Inter-Platform Coordination
The expedition demonstrated advanced coordination between multiple platforms: Atlantis provided surface support and real-time communication, Sentry conducted preliminary reconnaissance and detailed sonar mapping, while Alvin enabled direct human observation and targeted photography. This multi-platform approach maximized scientific efficiency while ensuring comprehensive documentation of the historically significant wreck site.
This technological integration represents the current pinnacle of deep-ocean archaeological capability, providing tools that previous generations of naval historians and archaeologists could not have imagined when USS F-1 was lost in 1917.
TECHNICAL SPECIFICATIONS: USS F-1 (SS-20)
Class Overview The F-class submarines represented an evolutionary step in early U.S. submarine design, essentially enlarged E-class boats designed by the Electric Boat Company. They were single-hulled boats with circular sections laid along the longitudinal axis and were the first U.S. submarines to incorporate bow planes.
Construction Details
- Builder: Union Iron Works, San Francisco, California
- Laid Down: August 23, 1909 (as USS Carp)
- Launched: September 6, 1911
- Renamed: F-1, November 17, 1911
- Commissioned: June 19, 1912
- Fate: Sunk by collision, December 17, 1917
Physical Characteristics
- Overall Length: 142 feet 7 inches (43.43 meters)
- Beam: 15 feet 5 inches (4.70 meters)
- Draft: 12 feet 2 inches
- Displacement: 330 tons surfaced, 400 tons submerged
- Hull Configuration: Single hull with circular cross-section
Performance Specifications
- Surface Speed: 13.5 knots
- Submerged Speed: 11.5 knots
- Test Depth: 200 feet
- Record Depth: 283 feet (86 meters) - world deep diving record holder in 1912
- Range: Limited by fuel capacity and battery endurance
Propulsion System
- Type: Diesel-electric configuration
- Surface Engines: New London Ship & Engine Company diesels, 780 horsepower
- Electric Motors: Electro Dynamic Company motors, 620 horsepower
- Battery: 120 cells in rubber-lined, open-topped steel jars
- Fuel Capacity: 11,500 gallons
- Propellers: Twin screws
Armament
- Torpedo Tubes: Four 18-inch (450mm) tubes, all forward-firing
- Torpedo Load: Four torpedoes
- Tube Design: Streamlined, rotating muzzle cap that eliminated drag when not in use
Compartment Layout The hull contained three compartments separated by partial strength watertight bulkheads: torpedo room with four torpedo tubes, control room/battery rooms with ballast control valves and hydroplane controls, and engine room.
Crew Complement
- Officers: 1
- Enlisted: 21
- Total: 24 crew members
Notable Design Features
- First U.S. submarines equipped with bow planes
- Small conning tower fairwater initially precluded bridge structure; temporary canvas structures were erected for surface operations
- Rotating torpedo tube muzzle caps made the submarine appear to have no torpedo tubes when stowed
- Diesel engines experienced reliability issues and were replaced in 1915
Operational History Notes
- Based primarily at San Pedro, California, with deployment to Pearl Harbor, Hawaii (1914-1915)
- Placed in ordinary (reduced commission) from March 15, 1916 to June 13, 1917
- Returned to full commission for development of submarine tactics with Pacific Fleet
PERSONNEL LOST AND CONTEMPORARY PRESS COVERAGE
The Human Cost: USS F-1's Final Crew
Of USS F-1's complement of 24 officers and enlisted men on December 17, 1917, only five survived the catastrophic 10-second sinking. The commanding officer and four men on the bridge escaped, while 19 crew members were trapped below when F-3's bow gouged a massive hole in F-1's port side forward of the engine room.
The 19 men who perished represented the dangers inherent in early submarine service, a duty that Naval History and Heritage Command Director Samuel Cox described as requiring "great courage just by volunteering for submarine duty in those days." Operating at sea has always been inherently dangerous, and even more so for early submarines, with factors including night operations, fog, speed, and radio miscommunications contributing to the loss of life.
Crew Composition and Service Context USS F-1's crew represented the typical composition of early submarine personnel: a mix of officers and experienced enlisted sailors who had volunteered for the hazardous duty of underwater operations. The submarine was operating under Lieutenant (j.g.) J.B. Howell's command and had been conducting development of submarine tactics as part of the Patrol Force, Pacific.
The tragedy occurred during what was described as a 48-hour engineering run and performance test, with F-1 operating alongside her sister submarines F-2 and F-3 in exercises designed to develop early submarine warfare capabilities. The loss represented a significant blow to the fledgling submarine service, which had already suffered its first major disaster in 1915 with the loss of USS F-4 and all 21 crew members off Hawaii.
Contemporary Press Coverage and Wartime Censorship
The initial public announcement of F-1's loss reflected the constraints of wartime information security and the Navy's early approach to managing submarine-related incidents. On December 18, 1917, the Navy Department issued a brief, cryptic press release to the effect that an American submarine had been lost "along the American coast." There were no details.
Limited Initial Disclosure The sparse initial announcement was characteristic of World War I-era military communication policy. With the United States having been at war for only eight months and submarine operations representing a critical new warfare capability, the Navy provided minimal information to prevent potential intelligence value to German forces operating off the American coast.
Because of wartime censorship, no details were ever released and as the years passed, the sinking of the F-1 became an almost unknown and virtually forgotten incident in American naval history. This approach differed markedly from later Navy practices regarding accident disclosure, reflecting both the exigencies of wartime operations and the Navy's evolving understanding of public information management.
Fifty Years of Classification Details of the tragedy remained secret for almost 50 years, with the incident subject to military "restricted classification" until government records became available in Washington around 1970. This extended classification period was unusual even by early 20th-century standards, suggesting that the Navy viewed the circumstances of the collision as potentially damaging to submarine program development or operational security.
The lifting of classification in 1970 revealed that the tragedy was caused, as are so many sea accidents, by a simple failure in communications during formation operations in foggy conditions off San Diego. The newly available records provided the first comprehensive public account of the circumstances leading to the collision between F-1 and F-3.
Modern Commemoration and Historical Recognition
The contrast between 1917's minimal disclosure and the 2025 expedition's comprehensive documentation reflects dramatic changes in both technology and naval heritage preservation practices. During the recent expedition, the research team held a remembrance ceremony on board Atlantis, ringing a bell 19 times — one for each crew member lost at sea.
"History and archaeology are all about people and we felt it was important to read their names aloud," said underwater archaeologist Brad Krueger, who participated in the dives. "The Navy has a solemn responsibility to ensure the legacies of its lost Sailors are remembered."
This ceremonial recognition represents a significant evolution from the Navy's 1917 approach, demonstrating contemporary commitment to honoring submarine service members and preserving maritime heritage. The reading of names aloud during the 2025 ceremony provided the public recognition that had been absent for over a century.
Legacy and Lessons Learned The F-1 tragedy contributed to the development of improved submarine communication protocols and formation maneuvering procedures that would prove essential as the submarine force expanded during World War I and beyond. The incident highlighted the critical importance of reliable inter-vessel communication during formation operations, particularly in reduced visibility conditions.
The evolution from secretive 1917 press coverage to comprehensive 2025 documentation illustrates broader changes in military transparency, historical preservation, and public commemoration of naval service. The 19 men lost with USS F-1 are now permanently documented through advanced archaeological methods and memorialized through formal naval ceremony, ensuring their sacrifice is preserved for future generations of submariners and naval historians.
Conclusion
The rediscovery and comprehensive documentation of USS F-1 represents more than an archaeological achievement—it serves as a bridge connecting the modern submarine force with its foundational history. The technical precision of the 2025 expedition, combined with its commemorative elements, exemplifies the Navy's dual commitment to advancing maritime science while honoring the sacrifice of those who came before.
The lessons derived from the F-1 tragedy—emphasizing robust communications, precise navigation procedures, thorough weather assessment, and coordinated emergency response—remain as relevant today as they were in 1917. As the submarine force continues to evolve with advancing technology, the fundamental principles of seamanship, safety, and crew interdependence that the F-1 incident illuminated continue to guide naval operations.
The 19 sailors who perished with USS F-1 on that December morning in 1917 made the ultimate sacrifice in service of developing America's submarine capability. Their legacy, now preserved through advanced archaeological documentation, serves as a permanent reminder of the courage required for submarine service and the eternal vigilance necessary to ensure the safety of those who serve beneath the waves.
For continued coverage of naval heritage and maritime archaeology, visit the Naval History and Heritage Command website and the Woods Hole Oceanographic Institution's research portal.
Sources
Primary and Contemporary Sources:
- Woods Hole Oceanographic Institution. "Expedition captures the first ever images of the wreck of a World War I submarine." Task & Purpose, May 24, 2025. https://taskandpurpose.com/history/navy-submarine-f-1-world-war-i/
- CBS News. "WWI submarine captured in never-before-seen images over century after it sank off San Diego coast." May 24, 2025. https://www.cbsnews.com/news/wwi-submarine-uss-f-1-images-san-diego-coast/
- Live Science. "American submarine, lost for over a century, discovered 'remarkably intact' off the coast of San Diego." May 23, 2025. https://www.livescience.com/archaeology/american-submarine-lost-for-over-a-century-discovered-remarkably-intact-off-the-coast-of-san-diego
- Fox News. "Scientists document WWI submarine wreck USS F-1 resting 1,300 feet underwater." May 25, 2025. https://www.foxnews.com/travel/never-before-seen-photos-reveal-wwi-era-submarine-1300-feet-before-surface-where-19-sailors-perished-1917
- WTOP News. "WWI sub captured in never-before-seen images off San Diego coast." May 25, 2025. https://wtop.com/national/2025/05/wwi-sub-captured-in-never-before-seen-images-off-san-diego-coast/
Historical References:
- Submarine Force Library & Museum Association. "The Loss of USS F-1 (SS-20)." January 8, 2014. https://ussnautilus.org/the-loss-of-uss-f-1-ss-20-2/
- Fox 5 San Diego. "Deep-sea technology captures images of WWI submarine, 100 years after it sank near San Diego." May 27, 2025. https://fox5sandiego.com/news/local-news/coastal/deep-sea-technology-captures-images-of-wwi-submarine-100-years-after-it-sank-near-san-diego/
- The Travel. "Wrecked U.S. Submarine That Disappeared For More Than 100 Years Found In Shockingly Great Shape." May 25, 2025. https://www.thetravel.com/wrecked-us-submarine-that-disappeared-for-more-than-100-years-found-in-shockingly-great-shape/
Institutional Sources:
- Woods Hole Oceanographic Institution. "Deep ocean technology offers never before seen images of lost WWI submarine." WHOI Press Release, May 21, 2025. https://www.whoi.edu/press-room/news-release/wwi-sub/
- Naval History and Heritage Command. "Official statements and historical records regarding USS F-1 (SS-20) loss and 2025 expedition documentation." U.S. Navy, 2025. https://www.history.navy.mil/
- Office of Naval Research. "Expedition support and official statements regarding USS F-1 deep-sea archaeological mission." U.S. Department of the Navy, 2025. https://www.onr.navy.mil/
- National Science Foundation. "NSF support for National Deep Submergence Facility operations and Alvin/Sentry systems testing." Referenced in WHOI press release and multiple news reports, 2025.
- University-National Oceanographic Laboratory System (UNOLS). "Research vessel operations and fleet coordination for USS F-1 expedition." Referenced in institutional partnerships, 2025.
Note on Sources: This article synthesizes information from multiple contemporary news reports of the 2025 Woods Hole Oceanographic Institution expedition, historical records from the Submarine Force Library & Museum Association, and official statements from the Naval History and Heritage Command. All sources were accessed between May 23-28, 2025.
Deep-sea technology captures images of WWI submarine near San Diego over a century after it sank
SAN DIEGO (FOX 5/KUSI) — A team of researchers captured high-definition pictures of a sunken World War I-era U.S. Navy submarine off the coast of San Diego, over a century after it was lost at sea.
The USS F-1 was involved in a training accident eight days before Christmas Day in 1917, which killed all 19 crew members on board.
With the help of advanced deep-sea imaging technology, researchers were able to capture high-quality images of the submarine’s wreckage, discovered more than 1,300 feet under the ocean’s surface just west of San Diego.
Researchers from the Woods Hole Oceanographic Institution (WHOI) dispatched a human-operated submersible called Alvin and another underwater vehicle called Sentry, both belonging to the National Deep Submergence Facility (NDSF), to capture the images. (See images below)
Photogrammetric reconstruction of the submarine USS F-1 showing the conning tower and collision damage that caused the sub to sink. (Image by Zoe Daheron, ©Woods Hole Oceanographic Institution)
“While these depths were well within the dive capability for Alvin and Sentry, they were technical dives requiring specialized expertise and equipment,” said Anna Michel, co-lead of the expedition and NDSF chief scientist.
The team conducted surveys of the submarine using sonar systems on Sentry and a research vessel, Atlantis. They also surveyed the wreckage of a Navy Avenger torpedo bomber that crashed near the area where the USS F-1 sank.
“We were careful and methodical in surveying these historical sites so that we could share these stunning images, while also maintaining the reverence these sites deserve,” Michel stated.
A remembrance ceremony later took place onboard Atlantis to commemorate the lives lost during the submersible’s training accident 100 years ago. A bell was rung 19 times in honor of each crew member lost at sea, according to a news release by the institution.
“As a Navy veteran, making this dive—together with another Navy veteran and a Navy historian—was a solemn privilege,” said ONR Program Officer Rob Sparrock, who was among those on board the Alvin. “Lasting nearly eight hours, there was time to contemplate the risks that all mariners, past and present, face.”
The surveys and high-definition images of the USS F-1 were gathered with the assistance of the Office of Naval Research, the University-National Oceanographic Laboratory System, Naval History and Heritage Command and WHOI.
