CZ Tarantule was supposed to be used in cases where explosives couldn’t be used due to a high risk of collateral damage. The Tarantule uses a modified .50 caliber blank round loaded from the breech of the 18mm caliber smoothbore barrel to propel the 70ml of water which is poured down the muzzle and sealed in the bore via a special plug. The muzzle velocity of the water jet is a whopping 3500 m/s or 11,483 fps.
https://www.thefirearmblog.com/blog/2022/04/27/cz-tarantule-prototype-water-cannon/
Hmm, if it is already a thing, why is the Tarantule considered so unusual?
The Tarantule is quite a massive take on the idea. Which is probably the reason it never took off. The niche a PAN fills is specific and rarely is a concentrated water charge of such a huge size as the Tarantule needed.
Imagine a 12 gauge shotgun that somebody remade as a .50 cal. That’s basically what’s happening.
In bomb disposal, big applications tend to be less focused directional things- like popping car trunks, which you can do with a factory made Boot Banger, or Jerry can with C4 duct taped to one side.