The Geneva Convention II hedges a lot wrt submarine warfare - few submarines have the capacity to take on many survivors .. they're already pressed for space.

You could ague they had an obligation to notify search and rescue ... at a time when the nearest search and rescue was already alerted and en route.

See: https://www.justsecurity.org/133397/sinking-iran-frigate-den...

and scroll down to Failure to Rescue IRIS Dena’s Shipwrecked Crew

> Exactly this was one of the charges against Admiral Doenitz at Nuremberg.

A charge that didn't stick, a practice engaged in by both the British and U.S. submarines

  In the aftermath of World War II, the issue of rescuing survivors following submarine attacks took center stage during the trial of Admiral Karl Dönitz before the International Military Tribunal at Nuremberg.

  After Allied attacks on a U-boat attempting to rescue survivors of an ocean liner, the RMS Laconia, Dönitz issued the Laconia Order, which instructed: “All attempts at rescuing members of ships that have been sunk, including attempts to pick up persons swimming, or to place them in lifeboats, or attempts to upright capsized boats, or to supply provisions or water are to cease.”

  The court held that the order violated the 1936 London Protocol on submarine warfare,  which required that the passengers and crew of merchant vessels be placed in safety before a warship could sink them.

  Yet, because British and U.S. submarines engaged in the same practice during the conflict, it did not factor the breaches of the law of submarine warfare into Dönitz’s sentence.

Ethically - the US forces under Hegeseth are behaving like arseholes and absolutely skating a line, the same objective (taking out the ship) could have been achieved in a number of less odious ways.

Trump loves rolling in this kind of mud.

They didn't have to pick them up. They could have surfaced (remember, it was KNOWN that there was no threat) and tossed out a few inflatable life rafts.