Mini Sub

Overview
The Mini Sub is the Tier 7 Boss Strike reward in the 16th Boss Strike against the Sovereign Navy and also the tier 5 prize in the 17th boss strike against Shrow.

Its first attack, Sonic Pulse, is a -type area of effect attack. Since most ships don't have heavy Crushing resistances, this attack can be used to weaken light ships or deal the final blow to a few bigger ships, such as the Battleship Raptor-Class. It is also effective against enemy subs. The main purpose of this attack is to weaken the enemy forces since it covers most of the opposing army's field.

The Mini Sub's second attack, Torpedo, resembles the -type attack of the "regular" Submarine, and is useful against battleships and enemy (Mini) Submarines. Combined with a crit chance and the extra damage caused by breach this attack can seriously weaken a Battleship or Sub.

While this unit is deadly, it is also very vulnerable itself. Players should be wary when using this unit against Gunboats, Destroyers, and the Minelayer Destroyer as this unit is very weak against -type attacks. Combined with the increased damage and critical chances, it is very possible for this unit to be taken out in a single turn by a depth charge.

Another enemy unit to fear is the Monster Grouper which can severely damage this unit as its attacks cause high damage and -type damage.

Attacks
Sonar=

Torpedo Tube=

Trivia

 * SONAR is not actually an offensive attack, but is the means for ships and submarines to navigate underwater, as well as detect obstacles and targets. In fact it was originally an acronym which stood for SOund Navigation And Ranging.
 * In real-life, smaller submarines are usually less vulnerable to depth charges because a direct hit is needed to kill a mini sub, where a depth charge detonated further away form a larger submarine would have the same effect.
 * The design of the Mini Sub is reminiscent of the Black Boat from the game Advance Wars: Dual Strike though the Black Boat can not submerge and has no offensive capabilities.