STB-21 "Dolphin" is a small special combat boat developed by the NE army.
It was the beginning of the development of this STB-21 that military personnel watched an introduction video of a British midget submarine on YouTube while on vacation.
Although it is a little difficult to steer, it is equipped with missiles, torpedoes, and fixed machine guns, and was adopted by the military because of its excellent firepower and usability.

Onboard weapons
· Two 330mm torpedo launchers
· Two 30mm fixed machine cannons
· Anti-ship missile launcher (1 missile installed + 1 missile in the ammunition storage)

Onboard gimmick
· Steering trunk operation
· Operation of the torpedo launch pedal
· Operation of missile launch buttons
· Operation of propulsion adjustment lever
· Operation of the machine cannon shooting button (new addition)

Activation gimmick (AG) operation
·AG1 = Unlock torpedo tube and activate torpedo
·AG2 = Launch of missile launcher and launch of missile launcher