Question regarding a gun mount on light craft

[Felix C]

Looks as a 7.92 twin mg. Sight is for AA use. How effective would this be against aircraft?
Please move to small arms if not relevant to naval.
I suppose this is early war Med(no shirt due to being warm) when attacking a/c had .303 and not later when fitted with 20mm.

[Felix C]

After further research have found twin 7.92mm fitted to R-boats as these are for close in defense.

[PT Dockyard]

This Zwilling mount was used on a lot of light craft. I have a book that shows this picture and the caption says the Black Sea.

Dave

[Felix C]

Thanks. Have read where using a .30 or near caliber automatic weapon at night in a surface engagement was useful in distracting the adversary. That would be 200-300 yards range. For AA use that is danger close due to the rapid closure rate.

[ThatZenoGuy]

Looks as a 7.92 twin mg. Sight is for AA use. How effective would this be against aircraft?
Please move to small arms if not relevant to naval.
I suppose this is early war Med(no shirt due to being warm) when attacking a/c had .303 and not later when fitted with 20mm.

Early in the war a dual .30 machinegun mount poses a greater chance to take out a plane than in late-war (where the odds quickly start becoming zero), but still not ideal. At minimum you want a .50, ideally at least a 20, and to ensure a single shot takes out the target, a 37-40mm.