Deep-sea submersibles are specialized underwater vehicles designed to explore the ocean's depths. They can withstand extreme pressure and are equipped with advanced technology for navigation, communication, and observation. These vehicles are often used for scientific research, underwater archaeology, and marine biology, allowing scientists to study ecosystems and discover new species. Many deep-sea submersibles are manned, carrying a small crew, while others are remotely operated. Notable examples include the Alvin submersible, which has made significant discoveries, and the Deepsea Challenger, which reached the Mariana Trench. These submersibles play a crucial role in expanding our understanding of the ocean.