I think if engine failure in singles was a likely as your instructors suggest, very few people would be flying. So long as you don't run out of fuel, and take life jackets, MY view is that a well maintained single over water is fine. But this is really one of those issues where you just have to form your own view.
That said I remember my first open water crossing with my family aboard and it was nerve wracking. Altitude is your friend of course.
Last edited by jecuk; 10th Oct 2012 at 23:05.