[WheelsAtLarge]

I don't know about OceanGate but carbon fiber is often used to save weight and still keep the same strength requirements. I wouldn't doubt that's why they did it. You can go bigger and still keep within the weight requirements. Carbon fiber is expensive relative to steel but in this case since they were looking to make it a tourist attraction then, I bet, it was economically advantageous. And in theory it can withstand an equal amount of pressure.

The big disadvantage is that when it fails it's catastrophic. It just shatters. There's no warning. At least with steel it bends before it fails. That's not the case with carbon fiber.

[ChatGTP]

How could weight be a problem in the ocean and why would carbon fiber be cheaper than metal?

Not much of this comment checks out ?

[WheelsAtLarge]

The vehicle needs to be moved around above the water. There's a limit to how much weight can be moved around on the transferring boats. So that's why weight matters.

As far as why fiber is a better choice, the bigger the sub the more people it can carry. the more people it caries the better the company can cover costs. Specially since the sub cost is a one time fixed cost and the supporting costs are recurring variable costs. So it's worth making the vehicle as large as possible. Long term a bigger sub will be a better choice to get to profitability.

It's all a guess on my part.

[ChatPGT]

For incidents like that the weight could be a problem, no?

I mean, a machine would have a hard time to make it come up.