Im sorry that happened to you. We travel about 3x a year across land and air to take cruises and visit our vacation property in the US, and while I carry the custody papers on me every time, I have only been asked when he was a toddler (he is now 12). Our passports have the same surname. I understand being asked to show proof at border crossings but find it weird to be asked on cruise especially on our Canadian passports where they can assume Ive already been asked to provide the proof upon entering the country. I guess we have just been lucky. I did just called MSC and they told me that custody paperwork is sufficient and the affadavit is specially for when the child is not travelling with a custodial parent. We've been cursing for 8 years and have never been asked upon embarkation so I just found this piece of information very weird.