geek,
> Are the National Park Service and the United States Park Police the same Law enforcement department
Going from top to bottom on the organizational chart...the US Park Police is a component of the National Park Service, which is a part of the US Department of the Interior.
> or do they operate on distinct frequencies?
The US Park Police and the National Park Service do have their own channels and are, to a degree, capable of each others channels.
> I am primarily intersted in the Battery Park/Statue of Liberty/Ellis Island coverage. I know the R&Ps at battery park are marked U.S.P.P.
What's an "R&P"?
> Are the names used interchangeably,
No.
> or does the NPS have their own law enforcement branch?
Yes. They are refered to as Park Rangers. The US Park Police only has posts in the New York Metro Area, the District of Columbia, and San Francisco. Park Rangers protect NPS properties nationwide.
> I hear a lot of references to "NPS" marine units, which I assume are actually U.S. Park Police.
Your assumption is incorrect.
> I was curious which frequencies above they operate on, as well as the units that patrol the waters around Battery Park.
US Park Police: 166.325R (136.5) Primary, with 166.6375 ($4F9) used around the Ellis Island area.
NPS frequencies vary widely depending on the recreational area.
Harbor patrols are performed by the NYCPD's Harbor Unit: 470.8375R (136.5) with assistance by the US Coast Guard: 164.9125R (P25).
yahoo! is your friend.
www.doi.gov /
http://www.nps.gov/aboutus/organization.htm (click on organization chart pdf hyperlink).
Don't forget, to complicate things a bit, the US Fish and Wildlife Service - another part of the Department of the Interior, also has it's own law enforcement component as well.
SCANdal