The video clearly shows you are way too low for flying above salt water.
Salt water mist into the drone. Drone dies.
Water droplets on the bottom sensor and you just may cause the Drone to auto-LAND.
TIP: DJI Drones cams have a zoom feature.
EDIT...
You controller can connect to the drone without any wi-fi whatsoever, regardless of where you are. You must log into your DJI account on your controller via wi-fi (or other Internet connection) occasionally. You won't be able to connect the...
What they are saying is... you could be on the moon with Darth Vader, and as long as you log in to your DJI account with a valid connection while on the moon, then disconnect from the wifi completely, you could fly your drone there immediately...