The USS Stein incident

The USS Stein (top) and the sonar dome of the USS Willis A. Lee (bottom), the same type present on the Stein. Images by PH2 Hensley (Wikimedia Commons, public domain) and the U.S. Navy (Wikimedia Commons, public domain) respectively.

One of the most intriguing encounters in cryptozoology is the attack by an unidentified animal on the United States Navy frigate USS Stein. It was first reported in the U.S. Naval Institute’s magazine (Johnson, 1978) and later featured in the TV miniseries Arthur C. Clarke’s Mysterious World (Flynn & Weigall, 1980) and its companion book (Welfare & Fairley, 1980). The exact details of the incident are hard to pin down. The location was not stated in Johnson (1978) or Flynn & Weigall (1980). Welfare & Fairley (1980) said it occurred near the Equator in the Pacific Ocean off South America. The date was not stated in any of these sources. Flynn & Weigall (1980) did say that it happened on the Stein‘s “maiden voyage”. This scant information matches the Stein‘s “shakedown cruise”, which traveled from San Diego to South America and back in March-May 1972 (Naval History and Heritage Command, 2015).

A photograph (left) and video screenshot (right) of damaged rubber from the Stein, from Johnson (1978) and Flynn & Weigall (1980) respectively. The numbers indicate two of the matching cuts demonstrating that these are the same section.

All three sources agree on the nature of the event. During its cruise, the Stein‘s sonar equipment suddenly malfunctioned due to increased noise feedback. When the ship returned to dry dock to make repairs, the crew discovered the cause of the malfunction. The insulating rubber coating of the sonar dome, which was attached to the front of the bow below the waterline, had been ripped open. The cuts covered ~8% of its surface (Johnson, 1978). Petty Officer Ira Carpenter claimed that the longest one was “about 4 feet long” (Flynn & Weigall, 1980). However, a photograph and video of a section of damaged rubber show the longest cuts to only be ~2 inches long (Johnson, 1978; Flynn & Weigall, 1980). Either Carpenter greatly exaggerated their size or the much larger ones were not located on this section.

A video screenshot of Forrest G. Wood holding one the hooks of the Stein squid, from Flynn & Weigall (1980). 

The culprit of the attack left behind numerous “teeth”/”claws” embedded in the cuts. Navy marine biologist Forrest G. Wood identified them as arm hooks from a squid (Johnson, 1978; Flynn & Weigall, 1980). C. Scott Johnson, a Navy biophysicist, alleged it was an “extremely large […] species still unknown to science” (Johnson, 1978). This statement is very doubtful, as video of Wood holding a hook shows it is roughly the length of his thumbnail (Flynn & Weigall, 1980). The average thumbnail length of an adult male is just 1.47 centimeters (Jung et al., 2015). Nonetheless, there is wild speculation about the squid’s size; a recent online article declared it was 150 feet long (Dunhill, 2022)! This article erroneously proposed it was a colossal squid Mesonychoteuthis hamiltoni, which are restricted to the Southern Ocean (Rosa et al., 2017).

The estimated size of the tentacular club (left) and whole body (right) of the Stein squid. The club and body are those of Onychoteuthis horstkottei from Bolstad (2010). The human silhouette is by Madhero88 (Wikimedia Commons, CC BY-SA 3.0).

In my opinion, the Stein‘s assailant was likely a hooked squid, a member of the family Onychoteuthidae. Onychoteuthids are characterized by two rows of large hooks on each of their two tentacular clubs. It may have been the clubhook squid Onychoteuthis horstkottei, which inhabits the equatorial East Pacific, or a closely-related species. In an individual with a mantle length of 7.5 cm, the longest hook length was 0.38 cm (Bolstad, 2010). Using these proportions and the estimated length of the hook held by Wood (1.47 cm) results in an estimated mantle length of 29 cm for the Stein squid. This is larger than the largest known O. horstkottei, which had a mantle length of 11 cm, but other species of Onychoteuthis reach this size (Bolstad, 2010). Although a highly tentative estimate, it suggests that the hooks probably belonged to a small squid.

References

• Bolstad, K.S.R. (2010). Systematics of the Onychoteuthidae Gray, 1847 (Cephalopoda: Oegopsida). Zootaxa, 2696, 1-186. https://doi.org/10.11646/zootaxa.2696.1.1
• Dunhill, J. (2022, September 14). The USS Stein monster: In 1978, a massive creature attacked a Navy frigate, shredding parts of its hull. IFLScience. https://www.iflscience.com/the-uss-stein-monster-in-1978-a-massive-creature-attacked-a-navy-frigate-shredding-parts-of-its-hull-65325
• Flynn, C. (Director), & Weigall, M. (Director). (1980, September 9). Monsters of the deep (Episode 2) [TV miniseries episode]. In J. Fairley (Executive Producer), Arthur C. Clarke’s mysterious world. Yorkshire Television.
• Johnson, C.S. (1978). Sea creatures and the problem of equipment damage. U.S. Naval Institute Proceedings, 104(8), 106-107.
• Jung, J.W., Kim, K.S., Shin, J.H., Kwon, Y.J., Hwang, J.H., & Lee, S.Y. (2015). Fingernail configuration. Archives of Plastic Surgery, 42(6), 753-760. https://doi.org/10.5999/aps.2015.42.6.753
• Naval History and Heritage Command. (2015, September 24). Stein. https://www.history.navy.mil/research/histories/ship-histories/danfs/s/stein.html
• Rosa, R., Lopes, V.M., Guerreiro, M., Bolstad, K., & Xavier, J.C. (2017). Biology and ecology of the world’s largest invertebrate, the colossal squid (Mesonychoteuthis hamiltoni): A short review. Polar Biology, 40(9), 1871-1883. https://doi.org/10.1007/s00300-017-2104-5
• Welfare, S., & Fairley, J. (1980). Arthur C. Clarke’s mysterious world. A & W Publishers.