Mike, flattery will get you anywhere! Actually, my own navigation system is simple. If it's big and brown, it's Australia. If it's big and white, I'm too far south.
Seriously, I have studied more navigation than I ever use in practice. I can do modern celestial and have some knowledge of the awful methods of 1912. I'd like to do more but you can't even get the tables of those days.
If you look at my little chart, you'll see that both Titanic and Carpathia were not where their navigators thought they were. By using the Traverse Table, I worked out where Rostron thought he was when he set out for Titanic. Had he really been there, he would have passed to port of Boxhall's boat. In fact, he first saw it on his own port side. Rostron seems to have been a bit further along his course than he thought. That's quite forgivable. The key to understanding much of the Titanic story is to know how they navigated in those days and the limitations of the methods. Rostron's last celestial fix would have been at about 7-30 that evening. When got the CQD, he'd been going on dead reckoning for five hours, so there was time for a small error to creep in, perhaps due to current. It all amounts to Boxhall and company being rather lucky. Carpathia just happened to be in the right place and on the right side of the icefield.