What would a planetary wet navy do in Star Wars?

How would a blue-water navy work on a Star Wars planet with an economy comparable to the United States around 2000?

Policing and counterinsurgency remain plausible roles, while mobile planetary-defence weapons face competition from space-based forces.

A conventional ocean fleet is difficult to justify where major forces can operate above the atmosphere. Hovering vehicles and other surface systems can cover some local tasks. Large mobile surface-to-orbit weapons are considered, although the need for protective shields complicates their value. The most convincing remaining roles are local security and counterinsurgency. The comparison applies to the fictional setting's technological assumptions.