Pace,
Slight difference. If I fly over water and the engine fails, I will have planned to have the survival equipment in place and ready to once I put her down and will know in advance how to egress. I can't very well survive a self-inflicted gunshot wound, no matter how much preparation I put into it.
I never said don't fly as high or leave yourself in a position where you have no outs. I actually said completely the opposite: do your proper planning in a manner that flying over water is simply a different consideration to flying over land. Perhaps this simplicity comes from years flying above the clouds where the only thing telling you you're over water is the colour moving map, but that's why I say treat water as a consideration rather than as a specific plan all to itself.
I'm always amazed at how people will plan more for a flight over water than they would flying over a major metropolitan area. Frankly, I would prefer ditching to have to find a place in a downtown core. Yet for most people they wont spend a second thinking about the city but will fret for days about water.