Mr Musk, it's to save the environment.

It's to preserve Earth.

 

Think about it.

 

Abundance of lithium = everything goes solar.

Fish breeding program = no overfishing, food production.

Transport of construction materials = Sea platform, Sea tower, Underwater city.

Later ships convert into cargo ships for shipment = Boost in economy for sales of products.

Natural resources as well. Whatever that can be gathered.

 

Trees grow back. Planned carefully.

 

Small price to pay for all the benefits.

 

You make them fully out of metal, that's not enough to reap the resources of the sea.