Whenever someone mentions a military submarine (it happens more than you think), the first weapon you probably think of is the torpedo. Partly because torpedos have been made famous in plenty of films, partly because they are just awesome (underwater missile? Yes, please) and partly because they are relatively standard fare for any sub, this is no surprise. Nonetheless, submarines are often equipped with plenty of other weapons that are both offensive and defensive.
Just look at that bad boy
Flak guns are one of the more common of these alternative types of weaponry and they serve a very specific purpose. These cannons are the most effective way to defend your sub from an aerial assault in Silent Hunter Online, so you’ll want to call on the services of your Watch Officer to set up your sub with one of these bad boys and make sure you get the most out of it. Aerial threats are not to be underestimated, so you had better get your hands on a shiny new Flak Gun a.s.a.p. and start blasting those badgering whirlybirds and their airborne buddies down from the wild blue yonder.