Does any one have any idea how deep sea regions like the CENTRAL_MED are designated as deep sea regions as opossed to coastal seas such as the EASTERN_MED??

In other words if I wanted to change The CENTRAL_MED into a coastal sea how can I do it- I know that it is possible because Wes in his MED_MOD 3.14 changed the entitre MED region into a deep sea region so feasibility is not a question, so what would I have to change in the Startpos files to make it happen??

And finally does the staus of any sea whether deep sea region or coastal sea have any bearing on its potential trade income??

Thanks a lot in advance.