I think the engine failure statistics disguise a huge standard deviation - because of the great average age of the GA fleet and the great variation in maintenance standards. But it's hard to collect data on this point because not enough engines fail enough times before they are scrapped.
Personally I fly happily over the channel at its widest point, wearing a life jacket and with a raft on the seat next to me, or on the back seat iof there is a passenger.
What I would not do is
- cross water beyond glide distance if the surface conditions would make life raft entry hard or impossible (e.g. now, with F7+ winds and heavy seas).
- fly at night over land when it's really pitch black
- fly in IMC when cloud is below say 300ft AGL
- fly anywhere if icing level is below MSA, unless the cloudbase is definitely above MSA all the way.
The above conditions (except for the last one) are basically Russian roulette, as far as I can see. The last one I am willing to risk if the layer isn't more than say 3000ft thick and I am doing a long flight to a much nicer climate...
But I am quite happy to takeoff in 200ft cloudbase and 1800m vis if right away down below is just calm water; water is water and is same everywhere
