One thing I don’t understand about crew aboard submercibles is why they need to go in to decompression chambers upon their resurfacing? Well I DO know that it’s because while they were under, the weight of the water makes the air pressure within the craft increase, and they need to slowly “decompress” when they come back up in order to avoid the “bends”.
My question is, why can’t they make submercibles that maintain surface air pressure within the confines of the submercible? Is this a tall order? I understand this would put huge strain on the outside of the craft, but surely technology is getting to the point where we can build super-strength materials capable of withstanding such forces?