While this may sound like a pretty ridiculous idea, The Triton Logging Company is a company that specializes in harvesting underwater lumber. The underwater forests are created by flooding due to new hydro-electric dams built throughout the world. There are an estimated 300 million trees that are now underwater and waiting to be harvested around the globe, worth some $500 Million USD.
Their primary tool is The Sawfish, a proprietary hybrid of an Unmanned Underwater Vehicle a logging machine. It is real and is actively harvesting underwater forests in British Columbia, Canada.
Bravo for unconventional ideas.