I am looking for a way to calculate a distance matrix between points, but not 'as the crow flies'. I want the distance to be calculated around a polygon layer.
Example 1: I have several fishing lodge points and I want to know the distance between them that a boat would drive. Boats cannot drive over land.
Example 2: I have fish survey points and I am interested in larval dispersion between protected areas. Fish larvae cannot go over land.
What is this analysis called? How do I do it?