One of my favourite failed launches has to be the Sept 1907 launch of the Italian ocean liner Principessa Jolanda . In those days it was apparently common to launch ships fully equipped and completed, however someone must have misjudged her balance and how she would sit on the water once she came, too quickly, off the slipway, because she began to slow list to her port side side. And kept going. And going. Until she was resting, completely submerged, on her side. It can't have helped if there were loose fittings and furniture, which would have all slid to the same side, as well as open or incomplete portholes. She also didn't have any coal aboard or ballast to balance out being top-heavy. The ship was scrapped from right where it was, and her sister ship was redesigned to be less top-heavy. She was gone in about 20 minutes, and never actually sailed. The sister lasted about three days before being sunk. When you look at the way liners were built, at least by the more famous British shipwrights, the hull and main boat decks would be completed, as well as at least some of the superstructure, however a significant portion of the ship would be completed after it was solidly in the water, tied again to a special portion of the dock while everything was finished. This way you knew how the ship would sit on the water. Biggest issue with most of these situations is based on their country. Rules like chain grade and how that relates to static vs dynamic weight is huge in all these situations. Maybe the tug boat was 5000lbs lighter than the static weight limit of the chain, but it was probably 2-3x too heavy if you calculated the dynamic weight, since it was swinging. And number of 1, the yacht, all they needed was a docking pole. One of the most overlooked but incredibly important personal boating accessories. Being able to stop yourself in flowing water is super simple but this guy must've bought it from someone who'd never sailed before.