my phantom 4 landed in fresh water only 1min then i took battry out then the phantom i put on rice after a few day i try to on the phantom cannot start and then i try chage battry the batry cannot full chage. which one problem battry or main board phantom?9/10 battery will be ruined but I have heard lots of success stories with drones dunked in water. Even after 6 months. As long as you took the battery out as soon as you got it, then leave it for a few days to dry out. If it landed in salt water you may need distilled water to rinse it off otherwise the salt will corrode the electronics
Neon Euc