Anyone reading the synopsis may be surprised just how little The Dressmaker focuses on the actual sinking of the Titanic and the investigation afterwards. Instead, the book's main focus is on maid Tess's life afterwards, and since Tess is just not that interesting, it was difficult to get immersed into the book. Also uninteresting was the love triangle involving Tess and two very different men, which seemed thrown in just to capture romance fans.
Even though Lucile was portrayed as very unlikable at times, she had a personality that dwarfed Tess's. This is unfortunate since Alcott had free rein with the fictional character of Tess, and she could have created a woman who would not be overshadowed by Lucile.
When the book delves into the investigations of the Titanic, I was completely enthralled. However, this was just not enough to elevate the other portions of the book. If you're interested primarily in the investigations, I would recommend looking to the internet.