How to build watertight containers that keep water out even if it is fully submerged? [duplicate]

Question

Examples of appliances I want to protect are: monitors, computers, and printers.

I have looked everywhere and I cannot find a solution where I can simply buy a box in the market. These are often times very small and will not fit the appliances I need to be protected.

Assumption is that the container will be used for home use in case there is a great flood. So the water pressure isn't likely to be too strong--not like submarines where they dive down to deep altitudes.

I can say that a submarine is a massive watertight container that can allow many people and equipment to live inside it. So, creating a watertight container should be possible with similar concepts. I wonder what materials and techniques I should look into to build one myself.

Answer 1

You need pelican cases. there is no need to reinvent the wheel here, you would spend much more money developing and building waterproof containers instead of buying readily available commercial products.

Pelican cases are used in media productions around the world to keep all kinds of camera gear, monitors and computers dry and safe.

I have worked on television productions that have used dozens of pelican cases to transport sensitive cameras and large media production gear to locations in wet and hostile environments here in Alaska.

I took my entire camera gear Outfit including multiple cameras and many lenses down the Grand canyon Colorado river In a 1620 pelican case, It kept it safe and dry through all of the rapids and being completely submerged for short periods of time. My laptop was in a pelican case in a raft that was overturned and submerged underwater for nearly an hour and stayed safe and dry.