Besides the US Airways 1549 which ditched into the Hudson, there's also been a few incidents of passenger aircraft ditching with a decent survival rate, at least in the years I've been flying. From the top of my head there's the Ethiopian Airlines 767 incident off of the Comoros Islands (about 50 survivors), the Garuda 737 which ditched into the Bengawan Solo River (only fatality was one of the cabin crew) and the Japan Airlines 747 which overshot the runway at Haneda and landed into a shallow lake. Am pretty sure there was a 747 at Kai Tak as well which landed in a typhoon and ended up ditching with everyone onboard successfully getting into the life rafts. So the safety procedures are there for a reason, even if it (thankfully) is a rarity.