Combatant ship

A combatant ship is a naval ship designed primarily to go "into harm's way."

A combatant ship is armed with offensive weaponry, although the ship and its weapons may be employed in offensive or defensive roles. Combatant ships and auxiliary ships form the two primary groups of naval vessels. The key discriminator is that, if even armed, auxiliary ship weapons are used for ship self-defense only.

Combatant ship operations include: anti-ship warfare, also known as surface warfare; air warfare; anti-air warfare; anti-submarine warfare; amphibious assault; and land attack.

Most types perform many of the combatant operations, see their respective articles for details.

The roles of combatant and auxiliary ships can overlap. An aircraft carrier's roles start with the traditional auxiliary roles of transport (of aircraft) and replenishment (of her battle group), but the ability to launch her aircraft for offensive strikes or defensive air cover makes her a prime combatant. The difference between a combatant amphibious assault ship and an auxiliary troop ship, both of which carry troops, is the organic ability to land the troops under combat conditions with landing craft or helicopters. Unarmed supply, research, and rescue submarines are properly auxiliaries.

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