The P-8 is a submarine hunter, and has a small weapons bay and drop chutes that can be used to drop torpedos and sonobuoys while in flight. I imagine they used the same capability to drop the survival packs.

There’s a pic of it here: https://www.twz.com/40859/the-case-for-stripping-the-p-8-pos...

(I have no opinion or endorsement of the other content in that site, just merely was looking for a picture)