"Dry submarine" in custodial injuries refer to
Suffocation: Near-suffocation may occur by means of a plastic bag placed over the head of the victim ('dry submarine'). Ref - Krishan Vij textbook of forensic medicine and toxicology 5e pg - 193
Beating on soles of feet
Tying a plastic bag over the head
Immersion of head in contaminated water
Suspending the accused by ankles
Sexual offences and infanticide