Why does Deep flight and other deep ocean vessels have very thick windows and walls?

Deep ocean vessels like DeepFlight are designed with very thick Windows and walls to withstand the immense pressure found at great depths. As water pressure increases significantly with depth, these robust materials ensure the structural integrity of the vessel, preventing implosion. The thick Windows also provide enhanced visibility while ensuring the safety of occupants and sensitive equipment inside. This engineering is crucial for exploring and studying the deep ocean environment effectively.