I've done 7 Just you trips and at 44 been the youngest on only two of them, but don't let the age thing worry you, everyone is in the same boat and there is always a good crowd, I have had a great time on every trip I've been on and only wish I'd started travelling sooner, there are always people in the group to eat and drink with or just to keep an eye on your stuff while you go for a dip in the sea.