The length was a bit hard to accept. Later I started looking into torpedoes and there are some real monsters that have existed, the Japanese Type 93 used in WWII is almost 30 feet long https://en.wikipedia.org/wiki/Type_93_torpedo .

The more modern Russian Type 65 is roughly the same size as the Type 93 https://en.wikipedia.org/wiki/Type_65_torpedo

Russia also has that 'Poseidon' unmanned mini sub that's basically the nuclear powered sub version of a UAV that's something like 65 feet long and is believed to be able to be launched from another sub like a torpedo https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_...