As it turned out I needn't have worried.
First embarkation . A remarkably straightforward procedure, especially to anyone used to air travel these days. Bearing in mind that we managed to turn up at what appeared to be the peak time it went pretty smoothly. Took about 40 minutes all together, probably less.
We did notice pretty early on that my wife and I were at the lower end of the age range. Anyone expecting anything else really hasn't done their homework though. That said there were a large proportion of folk in their 50s. One thing is certain though. In an emergency, there were some passengers who just weren't getting off the ship in a hurry. If I wanted to hang out with a younger set, I'd have headed for Ibiza.