1. a deep-sea research vessel designed to withstand extreme water pressure and carry observers to great ocean depths
Usage: nautical; scientific

Examples

• The bathyscaph descended to the ocean floor to study marine life.
• Scientists used a bathyscaph to explore the deepest parts of the Pacific Ocean.
• The famous bathyscaph Trieste reached the bottom of the Mariana Trench in 1960.
• Modern bathyscaphs are equipped with cameras and robotic arms for research.
• The crew entered the bathyscaph’s pressure-resistant sphere before diving.
• Oceanographers rely on bathyscaphs to conduct deep-water experiments.