Morale/Fatigue

Morale (also known as "Fatigue") is a hidden statistic within the game. Each ship has their own morale value. It ranges from 0 to 100 and has various boosts and penalties associated with it.

A high value of morale can be seen as an actual lack of morale. A value above 50 is commonly known as the "Sparkle" effect.

Morale regenerates at 3 points every 3 minutes (like Fuel, Steel and Ammo) and this regeneration is capped at 49 points, where it will simply stop regenerating.

Specific effects
When fatigued, ships will experience decrease in accuracy, increase in damage taken, and lower evasion rate.
 * Above 50, the ship generates a "Sparkle" on its image. This state of morale improves performance in general and has a chance to produce the "Great Success" from expeditions. There is no data to suggest that a value higher than 50 (The first threshold on which the Sparkle Effect appears) boosts performance further than 50.
 * At range 49 to 40, nothing happens.
 * At range 39 to 30, the "Mamiya Food Ship" button in the fleet composition window is flashing. This slightly decreases general performance.
 * At range 29 to 20 the ship shows a sad, orange smiley on it's face. This decreases general performance.
 * At range 19 to 0, the ship shows a screaming, red smiley on it's face. This severely decreases performance.

It takes about 20 minutes to go from absolute zero to Orange and another 10 to go from Orange to normal.

There is currently no proof that ships will sink more easily under a low morale state. However, given the performance cut they get from fatigue, it is not advisable to take them to battle like that in general.

Morale modifiers

 * 1) Returning to base after a sortie always incurs a 15 point loss. It does not matter if you finished the map in any way, were forced to retreat because your flagship was reduced to red health or you withdrew manually, the loss is always 15 points. This loss is subtracted from each ship after points gained during sortie were added. This makes the maximum possible morale 85.
 * 2) Returning to base after an expedition causes a 3 point loss which is only relevant if the ship has above 50 morale points as the natural regeneration of even the shortest expedition would be 15 points. At maximum morale (85, for practical purposes) it is possible to run 12 expeditions before the sparkle effect vanishes. A support expedition uses up more morale points, reducing morale by 5 after return if it doesn't trigger. Morale is reduced by 9 if the support fleet appears.
 * 3) Returning to base after an exercise (PVP Match) incurs no penalty, making a maximum morale value of 100 possible.
 * 4) Battle Ranks: A Complete Victory (Regular S Rank. Not Perfect Victory, which is S Rank + No damage taken) boosts morale of the sortied fleet by 1. A rank imposes no change. B rank lessens morale by 1. C rank lessens morale by 2. Defeat (D Rank) decreases the value by 3 for everyone.
 * 5) MVP and Flagship position: MVP grants +10 points to the ship while the Flagship gains +3 points. This stacks, giving a MVP Flagship +13 points. S Rank stacks on this as well, elevating it to +14 points. This applies regardless of battle rank.
 * 6) Night Battle: Starting a night battle incurs a 2 point loss for the entire fleet. Unconfirmed if this is the case with maps that are Night Battles by default but unlikely.
 * 7) Remodel: Remodel resets morale to 40 regardless of what it was before
 * 8) Repair: morale is reset to 40 after the repair is finished but only in the case of morale being 39 or less.
 * 9) Time: morale regenerates up to 49 at a rate of 3 points every 3 minutes. It will never decrease over time naturally, meaning that high (≥50) morale, aka sparkling, will never vanish unless the ship goes on a sortie, expedition or loses a PVP match with D Rank.
 * HP: At this point there is no information regarding morale loss based on HP lost. However, some loss seems to occur upon losing percentages of maximum HP.
 * 1) When a ship with 29 or less morale points is used in a battle morale is further reduced by 6.

Running 1-1 solo
When returning to port you incur -15 morale. As this map has 2 battles you are guaranteed +26 from Flagship + MVP in both nodes. This gives us the base value of +11. This can be modified by Night Battles (Avoid in most cases. Going from B (-1) to S rank (+1) would not change the final rating. Only when you're at C or D rating and know you can hit A or S is it advisable to go into night battle) and battle ranks. With both S ranks without Night battle, it would be +13 total.

A D rank decreases the points by 3, a night battle by 2. At the absolute worst outcome (Double D rank, double night battle) you would only gain one morale point in total. (-6 for 2× D rank, -4 for 2× Night Battle)

The best way would be to get through with as little damage as possible and repeat 3 (Assuming decent luck and a constant S rank in the first node and no D rank in the last as well as no night battles = +12 average gain per sortie. 12×3 = 36. 36+49 = 85) times, repair in-between as needed.

To decrease the chances of your ship getting damaged, you can send one or two level 1 DDs with her. You can choose to not resupply or repair them, and then use them for modernization or decomission them after 2-6 battles.

Just doing the first node will result in -1 morale, even if you perfect S rank it without a night battle. (-15 + 13 + 1 = -1)

Day Battle S Victory in Excercises
By getting a S rated victory in PvP exercises (all enemy ships reduced to 1 HP and unable to participate in further battle) without engaging in night battle, it is possible to give an entire fleet of ships the "sparkle" effect.

The flagship will gain +4, other ships +1, and MVP an additional +10. Thus, if all ships start at a morale level of 49, they will all gain the "sparkle" effect. Note that freshly repaired ships will typically take about 9 minutes to reach 49 morale.

This can be utilized to make gaining morale from 1-1 easier by quickly giving ships the "sparkle" effect before engaging in battle solo.