Falling down accidents, just like car crashes, are inevitable. Just a question of time.
To avoid falling down into water, try not to fly over rivers, lakes, resouvoirs or seas. Some people just fly them on land for sufficient long time before risking them to water surfaces.
The present quad drones may be as heavy as 1.2kg or heavier. Light to mild wind is ok. Do not fly when winds are very strong.
Choose flight path where you can rescue the down-drones after accident.
I have similar mentality after 1 flyaway and 2 falling down (all suffering from complete loss of control). Still practising and trying to find workable solutions to reduce some of the risks.
CE mode is up to 100M, while FCC mode could be up to 300M before video signal is lost.
I have just modified the camera signal antenna. Not sure how far it could reach. May be around 400-600M. At best may be 800M. But difficult to find horizontal testing ground with 800M flight path.