Panama/Coastline and Islands

Coastline in Panama, in particular with reference to the Pacific, it's a fuzzy concept, for several factors:

• tides in the Pacific are very ample;
• interaction among rivers, sea, and mangroves.

It's also not clear whether or not the coastline serves as administrative border, nor at which `admin_level`.

At the moment we use the coastline as border for districts and corregimientos (that's admin_level 6 and 8), while provinces (4) and the country (2) extend as far as the 12 maritime miles. we aren't aware of the legal situation.