One of the companies I worked for brought in Neal Petersen for a motivational speaker. (he wrote Journey of a Hope Merchant). He was a poor kid from South Africa (mixed race, I believe), who managed to build himself a boat and enter one of the world's prestigious solo around the world races. Man, the stories he told about being on the sea alone - the things that happened to his boat that he had to repair, the storms he had to deal with and the sheer loneliness of being that long by oneself - and he was in a race. I just could not imagine wanting my daughter to experience that.
My daughter is 16 and she's intelligent, strong, resourceful, creative but she's 16 and does not always exercise the best judgment. Sailing across the Atlantic and Pacific is a far cry from sailing across the North Sea (which this girl has done). If anything happens, she could be days from rescue. And the pirates - oh she's a juicy little tidbit. Heck, there's a reason I won't let my 16 year old walk in areas of downtown San Jose by herself - let alone purposely navigate her way through pirates?! I know the alternative is Cape of Good Hope which is very treacherous but seriously.