Drones launched from submarines are already a thing: https://www.defensenews.com/naval/2020/12/07/the-us-navy-wants-to-find-ships-to-kill-using-aerial-drones-la

Drones launched from submarines are already a thing: https://www.defensenews.com/naval/2020/12/07/the-us-navy-wants-to-find-ships-to-kill-using-aerial-drones-launched-from-submarines/ https://www.defensenews.com/naval/2020/12/07/the-us-navy-wan... They use tubes for launching flares and buoys that the subs are already equipped with, and perhaps in the future also the larger vertical missile tubes for bigger drones.