UV to Soft X ray can be directed by lenses to the Seabed. Fluorescent returning photons, if they occur can be concentrated by parabolic reflection, and Charge Couple Detectors.

The returning photons can be plotted to make iso-fluor charts.

Said charts will show where the best ore is on the seabed for a wide variety of metals.

A submarine style vessel directed to the surface by a taut wire can raise tons of the best ore using only re-charge-able electricity and re-charge-able compressed air.

Every time the sub brings a load to the barge on the surface it gets totally recharged so it can go back down and bring up another heavy load of ore.

I have written four books on this and they are on Amazon.com

This is not science fiction. It is future commercial business.

The seabed has some very good stuff.

Somebody will decide to go get it.

Efficiency in finding and bringing is the key to profit.

My books run about $3. There are people who have that much money.

Elon has $3.