Lardy, there are such a variety of different glass-bottom boats in Sharm, you can afford to check out several and satisfy yourself before booking, that they have what you consider to be essential. Last time I was there they had some that looked almost like submarines. Very modern, and, I would imagine, equipped with adequate safety equipment. It must be big business in a resort the size of Sharm so public opinions regarding safety would be a must for operators in a competetive situation.

Hi
We went to Sharm last October, and did the glass bottom boat trip. I have 2 children who were 3 and 9 at the time. The worst part of it was getting from the speedboat onto the floating jetty, then onto the boat. I was petrified (but then again I am scared of jumping in a swimming pool, flying etc!!) the kids were fine though!!. We were given a jacket on the speedboat to get to the glass bottom boat, which we returned to them when we got off. The boat itself was safe enough. We were on top of the deck on its return to "base", but there was railings around the top of the boat, so you couldnt fall out.
I am not sure how possible it would be to check the boat out prior to going on it, as you'd have to get the speedboat to check it out.
I felt it was safe enough for my two brats!!! and they loved it.
Hope this helps

Best to check with the individual boats...
But - last time we were in Egypt the watersports centre had even started insisting that adults used life-vests on the plastic canoes..

Thanks all!