I don't need an engineer to tell me not to take a two-engine a/c overwater at night in Class II navigation regardless of the MEL. Some U.S. Airlines have a gentleman's agreement(although I haven't seen many gentlemen in airline mgt. the last few years) they won't dispatch under these conditions at night giving them the MEL relief to dispatch in the day. However, not a 'Bus driver. Newer Boeing(777, 787) have more backups. Won't do it on 757/767/737. Rather be tried by twelve than carried by six.