A "blue water navy" encompasses one key concept that the PN lacks - Expeditionary Warfare. The PN can't support ships overseas, it doesn't have the replenishment and logistics capabilities. It can't project power.
According to the US Defense Security Service"
The Defense Security Service of the United States has defined the blue-water navy as, "a maritime force capable of sustained operation across the deep waters of open oceans. A blue-water navy allows a country to project power far from the home country and usually includes one or more aircraft carriers.
Here's a bit about what makes the US Navy a blue water force:
Expeditionary Warfare
The Navy and Marine Corps have put in place a well-crafted transformation strategy to ensure that the nation has the naval expeditionary forces--ships, aircraft, weapons, and systems -- to carry out the full spectrum of roles, missions, and tasks in the new century. Expeditionary Warfare is the foundation for 21st-century peacetime forward deployments, responses to crises world wide, and warfighting to protect America's citizens and friends and vital U.S. interests wherever and whenever they might be at risk. It is the essence of naval operations from the sea--anytime.anywhere. Marine Corps forces have long provided a scalable, tailorable and expeditionary combined-arms option, enabling joint commanders to deal with a wide range of contingencies. For decades, however, Marine power projection has included a deliberate buildup of combat power ashore. This buildup required the establishment of a force beachhead, with relatively fixed fire support, logistics, and command and control positions located ashore. Only after naval forces fought ashore and established a beachhead would the MAGTF begin to focus its combat power on the Joint Force's operational objective. A combination of naval initiatives in advanced mobility, fires, and sustainment capabilities, leveraging substantially enhanced information connectivity, will enable future Marine forces to be employed in a dramatically different manner, making them an even more effective tool of national power.
Current and programmed amphibious assets predominantly fall into four Branches of the Expeditionary Warfare Division (N75): Special Operations (N751), Mine Warfare (N752), Amphibious Warfare (N753), and Explosive Ordnance Disposal (N757). The provided links offer a glimpse into some of the Division's priority programs and identifies the naval amphibious capabilities required by the Navy's expeditionary warfare forces of 2010 and beyond. All of these programs are essential to, and support the Navy and Marine Corps fundamental and enduring roles: sea control and maritime supremacy, power projection, strategic deterrence, forward naval presence, and strategic sealift.
At the most basic level, an amphibious force consists of a Navy element - a group of ships known as an amphibious task force (ATF) - and a landing force (LF) of U.S. Marines (and occasionally, U.S. Army troops). Together, these elements - and supporting units - are trained, organized, and equipped to perform amphibious operations. Now and in the future, commanders will have the ability to size and task-organize amphibious forces to accomplish a wide range of specific missions.
The resulting forces may range from a single Amphibious Ready Group/Marine Expeditionary Unit (Special Operations Capable) [ARG/MEU (SOC)], to a larger organization capable of employing a Marine Expeditionary Brigade (MEB) or even a Marine Expeditionary Force (MEF).
Amphibious forces must be capable of performing missions ranging from humanitarian assistance and disaster relief to major theater war (MTW). Additionally, they can be configured and deployed to operate at various levels of conflict and in multiple theaters simultaneously. They can provide a presence that may preclude adventurous actions by a potential belligerent. Because they are seabased and because the decision to position and engage amphibious forces will always be easily reversible, amphibious forces greatly expand the repertoire of available response options. Among other national resources, they are particularly well placed to provide a demonstration of U.S. commitment and resolve to friends and allies as well as adversaries. Normally two to three ARGs are forward deployed: one in the Mediterranean / Arabian Gulf-Indian Ocean area, and one or two in the Western Pacific area. The other ships of the ARG are either working up to deploy, in transit, or in overhaul. One ARG/MEU is forward based in Sasebo and Okinawa Japan.
In most cases, the ATF will be deployed under the protective umbrella of an aircraft carrier battle group (CVBG), which provides cover for the ATF and combat support to operations ashore. Ships of the ATF are capable of embarking and supporting other forces when the mission requires, including U.S. Army, Special Operations Forces (SOF), or other joint and combined forces.
The ATF will be sized and organized to support landing forces ranging from the smallest to the largest. It will consist of a mix of amphibious ships, support ships, and perhaps Maritime Prepositioning Force (MPF) assets, which carry equipment and sustainment for Marine forces. In most cases, the ATF will be deployed under the protective umbrella of an aircraft carrier battle group (CVBG), which provides cover for the ATF and combat support to operations ashore.
A forward-deployed MEU (SOC) is the standard task-organized force used for most peacetime presence and smaller-scale, crisis-response missions. These smaller Marine Corps units can be "mixed and matched" to create larger and more capable MAGTFs. The MEU (SOC) deploys onboard amphibious warships - three-ship amphibious ready groups - which carry the helicopters and amphibious assault vehicles that transport Marine combat and support elements ashore, as well as the vertical/short take-off and landing (V/STOL) aircraft - both fixed- and rotary-wing - that provide integrated air support.
The Navy's 21st century amphibious fleet will eventually include 36 ships, intended to form 12 ARGs. Each ARG will normally consist of a large-deck amphibious assault ship, an LHA, LHA (R) or an LHD; an amphibious transport dock of the LPD-17 class; and a dock-landing ship of the LSD-41 or LSD-49 classes.
The Operational Maneuver from the Sea concept was published 4 January 1996 by the 31st commandant, General Charles C. Krulak. Like its predecessor - the approach to amphibious warfare developed at Quantico during the 1930s - OMFTS was a response to both danger and opportunity in a fluid strategic environment. The danger, summarized by the phrase "chaos in the littorals," originated with the myriad forces of national aspiration, religious intolerance, and ethnic hatred that marked the post-Cold War world. The opportunity came from significant enhancements in information management, battlefield mobility, and the lethality of conventional weapons.
OMFTS foresaw that a new series of threats and enhanced tactical capabilities would produce significant changes in the Marine Corps' operational environment. The nature of war remained the same, and the Corps' fundamental doctrine of maneuver warfare remained as valid as ever before, but "chaos" and technology would inevitably affect where we fought, whom we fought, and how we fought. OMFTS understood the need for military innovation; it encouraged debate and experimentation and provided a framework for Marines, Sailors, civilian employees and contractors within which to turn concept into reality.
As the naval white papers .From the Sea and Forward.From the Sea provided the foundation for the OMFTS concept, OMFTS spawned the tactical concept, Ship-to-Objective Maneuver, as well as the operational and tactical sustainment concept, Seabased Logistics. These and other forward-looking concepts, such as Sustained Operations Ashore (1996); A Concept for Future Military Operations on Urbanized Terrain (1997); Concept for Future Naval Mine Countermeasures in Littoral Power Projection (1998); and Beyond C2: A Concept for Comprehensive Command and Coordination of the Marine Air-Ground Task Force (1998) have driven Marine education and training and research, development and acquisition. These concepts in turn have become integral elements of the Marine Corps' capstone concept, Expeditionary Maneuver Warfare, published in November 2001.
OMFTS fuses amphibious ship and landing force maneuver to create and exploit opportunities in time and space to project amphibious power ashore as seamlessly as possible. The impact of this kind of maneuver warfare was foreshadowed in Operation Enduring Freedom, when Marines seized a forward operating base in Afghanistan, approximately 400 miles inland from their seabase in the Arabian Sea. However, though the Marines successfully demonstrated the viability of these new warfighting concepts with current platforms, they will not be truly realized until they are married with the future elements of the "mobility triad" - the Advanced Amphibious Assault Vehicle (AAAV), the MV-22 Osprey tilt-rotor aircraft, and the Landing Craft, Air Cushion (LCAC).
The ideas and direction in OMFTS still continue to frame and guide Marine Corps thought and action, and have also had influence beyond the Marine Corps.
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This force, the USMC, has the means to project power far from US shores. It has replenishment and logistics support, inter-operational and trans-service capabilities with the USN and USAF and isn't confined to US or regional waters.
The PN doesn't have the same power-projection capabilities. It lacks logistical support and replenishment and can't sustain long-duration deployments in deep ocean waters. The PN is a Green water navy. That is to say it's one that can operate effectively in littoral water.
India, China, Brazil, South Korea, these are strong naval powers, but even they lack overseas support. The US, UK, France and to a lesser degree Russia and japan, these nations and their navies can support long-term overseas operations.
. Just being realistic
! The PN is strong in its region, but away from its shores it would be exposed badly.
