"The Shallows" is not based on a true story; it is a fictional thriller directed by Jaume Collet-Serra. The film follows a surfer, played by Blake Lively, who becomes stranded on a rock 200 yards from shore while being stalked by a great white shark. While the movie draws on real-life elements of shark encounters and the ocean's dangers, the specific plot and characters are created for entertainment purposes.

"The Shallows," released in 2016, was not considered a flop. The film, starring Blake Lively as a surfer facing a great white shark, had a production budget of around $17 million and grossed approximately $119 million worldwide. This strong box office performance, combined with positive reviews and a solid fan base, helped it achieve commercial success, making it a profitable venture for Sony Pictures. Thus, it can be classified as a success rather than a flop.

Yes, Blake Lively did perform some of her own surfing stunts in "The Shallows." To prepare for her role, she underwent extensive training and took surfing lessons. While a professional surfer was used for some of the more dangerous scenes, Lively was actively involved in many of the surf sequences, showcasing her commitment to the role. Her dedication added authenticity to the film, which revolves around her character being stranded on a rock while being hunted by a shark.

Yes, Blake Lively lost weight for her role in "The Shallows." To prepare for her character, she underwent a rigorous fitness regimen and followed a strict diet. Lively's transformation was part of her commitment to portraying a surfer stranded on a small rock while battling a great white shark. She aimed to achieve a lean and toned physique to reflect the physical demands of the role. The film showcases her dedication to both her performance and the visual aspects of her character's survival.