Bathysphere technology evolves from 1930s steel sphere design to contemporary titanium alloy construction. Grade 5 titanium (Ti-6Al-4V) enables 40% weight reduction versus steel. Spherical geometry optimization minimizes stress concentration. Acrylic & glass viewport technology enables optical clarity. CO₂ scrubbing systems enable 8-12 hour missions. Modern bathyspheres achieve 6,000+ meter depths & 600+ atmosphere pressure resistance.