waterproof-container-dat

• PVC tube
• acrylic box

PMMA tube

• PMMA-dat

inside

aluminum canister

• Theoretical minimum: <1 mm for a tiny cylinder.
  
• Practical safe design: 3–5 mm aluminum alloy (6061-T6) cylinder for 100 m depth.

ref

• waterproof - waterproof-container

• waterproof-dat