Marine Hub Cornwall has formally agreed a new collaboration with Marine Energy Wales to become leaders in marine renewable energy.
The organisations have signed a memorandum of understanding to work together on areas of common interest and to share their knowledge and expertise.
It is in line with a trend to get maximum benefit from the available resources and to develop technologies more quickly than might otherwise be possible.
"Our draft Welsh National Marine Plan highlights the need to join up with neighbouring regions, including the south west of England, to identify future opportunities and potential issues," said Welsh Cabinet Secretary for Finance Mark Drakeford.
"By working together we can help achieve our shared vision of clean, healthy, safe, productive and biologically diverse seas, creating sustainable economic benefits for both regions."