During events, qualified players gain access to special maps, which usually pertain to specific World War 2 battles; the only exception was a tie-in to the anime Aoki Hagane no Arpeggio: Ars Nova. Event maps stay up for about two weeks and are popular for farming ships not found in normal sorties.
While sortieing in specific event maps, special Abyssal Fleet bosses may be encountered on predefined nodes.
Starting Spring 2014 event, LoS 
-based checks were implemented. A fleet's total or equipment LoS affects movement through the map nodes and whether you reach the boss node. Since then, this mechanic has been implemented into extra operations maps.
Event List
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| Sortie! Operation Rei-Go!|link=Winter 2016 Event|class=fadein |
Tips
- The standard requirements to participate in an Event are:
- At least a 75% sortie win-rate. This is shown in the Fleet HQ Stats page.
- At least 5 free ship slots for new kanmusu to join before sortieing.
- At least 20 free equipment slots before sortieing.
- There are several special mechanics that have been included in recent events:
- Ship Locking is perhaps the most important, where each ship used in a locking map receives a colored stamp, even on easy difficulty. These ships can only be used in following maps that permit that color stamp; new ships will have to be used for those cases. Sometimes Easy difficulty allows admirals to get around ship locking requirements.
- Difficulty settings have been implemented, resulting in easier or harder enemies with lesser or greater rewards. Difficulties also sometimes ship drops as well as drop rates. When dealing with ship locking, sometimes the 'Easy' difficulty will allow already-locked ships, although doing maps on easy will still put the stamp on new ships.
- Combined Fleet mechanics are often implemented on some maps during events.
- Limited-time quests are sometimes required to unlock the next map.
- A stockpile of
resources & 
buckets. Experienced admirals may have suggestions.
- Common knowledge says that resources' natural regeneration will allow the completion of all event maps in the usual two-weeks window. However, it depends on the mercy of the RNG for the fleet's consumption, damage dealt and received, paths taken, and the number of times required to clear an event map.
- Buckets do not naturally regenerate. It's highly recommended to stock up before the event.
- An example reccomended stockpile: 150,000 fuel and ammo, and 100,000 of steel and Bauxite.
- Fuel is often considered the most important resource, as it is required for both sorties and repairs. Bauxite is required for the massive quantities of planes required for Carrier Task Forces. Ammo is readily consumed during battles, and steel is important to repair your ships. Remember that Buckets will not cut down on the resource costs of repairs.
- Although it's also a general rule-of-thumb, it deserves extra mention here: always have at least two of each ship type ready & leveled as the event maps' fleet composition requirements will not be known beforehand.
- However, ship locking has made this even more important. Though on Easy Difficulties (see above) ship locking is not enforced, it can cut down on possible rewards from clearing maps; not having a well-spread fleet can reduce effectiveness throughout the event!
- Remember to plan for possible combined fleet actions as well: Having several leveled standard carriers and light carriers are important for Carrier task forces; having high-level battleships and cruisers is important for surface task forces; and Heavy Cruisers, Torpedo Cruisers, Destroyers and a Light Cruiser are needed for the escort force.