As reported by Navy Recognition website,
displayed a supercavitating torpedo
it’s developing at the MADEX 2017 International Maritime Defense Industry
Exhibition held in October 2017 (1).
Development began in 2013 and at sea tests will take place around 2020. South Korea
The “vehicle” as it’s referred to in the article, is 125 mm (~5 “) diameter, is solid fueled, and has a top speed of 100 m/sec (around 200 kts).
If one believes Russian reports (always a risky business!), their supercavitating Shkval torpedo is 533 mm diameter, 200 kts, and 20 km (~12 miles) range.
Iran supposedly is developing a reverse engineered version of the Russian Shkval and a German firm developed a supercavitating torpedo although it never transitioned to a service weapon.
The takeaway from this is that the US Navy is falling significantly behind in torpedo development. The Navy’s standard heavyweight Mk48/ADCAP torpedo was designed in the 1960’s and became operational in 1972. There has been little development since then although some effort has been directed towards enhancing shallow water performance. Beyond that, though, torpedo development has been stagnant.
On a related note, the major challenge with a supercavitating torpedo is guidance. The formation of the air "bubble" that the torpedo travels in is deafeningly loud as far as sonar guidance is concerned. Supercavitating torpedoes are blind. Supposedly, a Russian version was intended to sprint to the target location and then slow down to "normal" torpedo speeds in order to acquire the target.
Torpedo development is one of several areas that the Navy has, bafflingly, neglected. Offensive mine warfare has all but halted, mine countermeasures have atrophied to near non-existence, naval gun support is non-existent, anti-ship missile development has only recently made any advancements after many years of neglect and, even now, significantly lags Russian, Chinese, and Indian weapons.
The Navy’s myopic focus on new Burke, carrier, and LCS funding and construction has led to neglect of vital but less “sexy” weapons, equipment, and systems. We are now being surpassed by friend and foe alike in many of these areas.
(1)Navy Recognition website, “MADEX 2017:
Developing a Supercavitating
Torpedo”, South Korea 10-Nov-2017,