GFP Hull Classifications:
GlobalFirepower.com (GFP) takes a rather conventional approach to hull classifications regarding per-country naval assets. Below are descriptions of each type considered:
Aircraft Carriers
These are either conventional- or nuclear-powered forms showcasing an expansive flight deck with hangar elevators for access. This surface is used for the launching and retrieval of fixed-wing aircraft (as a primary function) and rotorcraft (as a secondary function). In modern navies, Aircraft Carriers represent the flagship of the fleet, making them vital assets. Only a few select nations maintain an aircraft carrier as part of their surface fleet.
Helicopter Carriers
The Helicopter Carrier primarily supports rotorcraft and may offer facilities for the operation of Vertical Take-Off and Landing (VTOL) fixed-wing aircraft such as the F-35 and AV-8B 'jump jets'. These vessels are typically dimensionally smaller when compared to their Aircraft Carrier brethren. Provision for operating UAVs may also be seen in these vessel types.
Destroyers
Destroyers are the largest named, non-carrier ship type in modern fleets (not including Cruisers which are used by only a few powers). They are powerful, multi-mission oriented hulls with a broad array of sensors, processing systems, and weaponry and can support one or more rotorcraft from their included flight deck. Some forms are mission-specific, focusing on airspace deterrence or submarine hunting as primary roles.
Frigates
Frigates are the economical answer to the Destroyer, given roughly the same Blue Water / deep water capabilities and broad weapons / mission set. Similarly, they can support rotorcraft and operate independently or as part of the main fighting fleet. Their hull design bridges the gap between the dimensionally larger Destroyer and the smaller Corvette.
Corvettes
Corvettes typically represent the 'smallest' named vessels of the fleet. These are relatively compact hulls capable of operating in Blue Water environments as well as close-to-shore depending on draught depth. Corvettes can prove to be an economical measure for specific powers finding Frigate types out-of-scope and can also serve well those nations showcasing long-running coastlines.
Submarines
Conventionally- (diesel-electric) and nuclear-powered submersible hull designs are grouped together in the GFP analysis. Additionally, there is no distinction made between dedicated-attack, ballistic missile, and nuclear-attack types. Compact 'midget' submarines are also included as they still form portions of some fleets (as is the case for North Korea and Iran).
Patrol Vessels
The Patrol Vessel category is purposely broad and includes Offshore Patrol Vessel (OPV) types as well as gunboats, missile boats, fast-attack craft, and - in some cases - riverine assets. These boats are given shallow draughts for their specific operating environments and will typically serve as deterrent and enforcement assets in the grand scheme of the surface fleet.
Mine Warfare
Mine Warfare and Mine / Countermine assets are a generally overlooked portion of any surface fleet but prove just as critical as other designs particularly in times of war where their capabilities allow for denial of strategic waterways or participation in 'siege tactics' against harbors and ports. The GFP analysis reflects their importance in modern naval warfare.