Seabed Mining Investment Opportunities

I've recently come across a couple articles about seabed mining and it seems to me like it has the potential to become a profitable industry at some point in the future. I was wondering if there were any investment opportunities available to amateur investors (I have a Robinhood account), but I couldn't find much. The only publicly traded companies involved in seabed mining that I could find were Nautilus--which went bankrupt last year--and Maersk--which isn't quite as specialized as I was hoping. Do any of you know of any other companies involved in seabed mining or have thoughts on it as an investment opportunity? Thank you!