Dolphin.

This is coolbert:

From the Internet web site The Aviationist and thanks to You Tube Russian naval aviation deploys [an exercise] a naval sea mine of  prodigious size.

"Watch A Russian Navy Il-38N “Dolphin” Load A Superlarge Sea Bottom Mine For Anti-Submarine Warfare Exercise"

"For the first time, five Russian Navy Il-38 and Il-38N aircraft have taken part together in an Anti-Submarine Warfare exercise laying sea bottom mines." Look at the size of that mine!

See previous blog entries [with additional embedded links] the efficacy of the naval sea mine unquestionable:

https://militaryanalysis.blogspot.com/2020/04/port-arthur.html

https://militaryanalysis.blogspot.com/2018/12/bloch-i.html

coolbert.