In Naval Fleet Assault, the competing teams play the role of escorts to a naval fleet, and must fight to sink the enemy's while defending theirs. A fleet is composed of a flagship aircraft carrier accompanied by smaller frigates, destroyers, Aegis ships (a unique addition to this mode) and a single battlecruiser, all of which boast greatly increased health to withstand assaults. The various ships of a fleet display various traits, such as Aegises being able to intercept missiles and bombs with point defense weapons and carriers having extremely high health at the cost of possessing no means of self-defense, but all units as a whole display major aggressivity against players that get too close to them.
The left side of the HUD displays the current integrity value of both fleets, which decreases from 100 as ships suffer damage and are sunk. A match ends when the timer reaches zero or either fleet is completely destroyed. The fleets' health display is surrounded by bars denoting the availability of "Strategic Attacks", a system similar to killstreaks that provides a team with the aid of NPC actions to aid in weakening the opposing fleet. A total of five Strategic Attacks are available, represented on the HUD as missile icons:
- Missile Barrage: The player's vessels fire a missile barrage at the enemy's fleet.
- Hornet Airstrike: A squadron of F/A-18F Super Hornets launches an airstrike on the enemy's fleet.
- Artillery Barrage: The player's fleet fires a cannonade of artillery at the enemy's fleet.
- Bombing Run: A trio of B-1B Lancers launches a carpet bombing on the enemy's fleet as they circle above it.
- Cruise Missile Attack: The allied ships launch anti-ship cruise missiles at the enemy's fleet. Most damaging Strategic Attack, but has a ten-second delay between activation and impact.
Similar to standard Team Deathmatch, Naval Fleet Assault takes place on several maps inspired by those from Online Co-Op Missions.
- In rare cases, there is a possibility that a match may continue for the remaining time limit even when a fleet has been completely destroyed.
- During the first Naval Fleet Assault ranking event on October 2014, the promotional banner displayed a portrayed the game's mascot, Nugget dressed as Nicholas A. Andersen, including his moustache and cap.