When the Titanic was built in Belfast the dock was dug out below sea level . They then shored up a massive steel door made of steel with rubber seals around it to keep out the water. When Titanic was ready they opened the door slightly to fill the “lock” and then floated her out to sea nice and safe without and drama or damage where it duly sank ….!
It looked better in the old days with the backwards style launches and that made a smaller wawe too. So why sideways now? To save space maybe. Looks pretty good with the massive wawe though. Check the video below