Well, small hulls and big guns doesn't do too well together, even the danish Diana class which are part of the regular navy carries only heavy machine guns, 12.7 mm.

We had some examples in the Swedish navy where the higher powers had the notion that the small patrol vessel must have a (potent) gun. So the built them with a 40 mm Bofors. Unfortunately thar gun weighs about 3.5 tons and since it was placed rather high on a vessel displacing about 47 tons, well it's influence on stability was rather... well interesting. At the end they had the gun removed and the only weapons carried where sidearms and two LMG:s. Size actually matters, at least when it comes to the laws of physics...
Regards
Göran

Thanks for that enlightening information. I always thought if something's battleship grey & floats, it's got guns !!

They (MHV 900 and 800 class) can carry two light machine gunsfiring standard NATO 7.62 x 51 ammo, but they are usually not mounted. These vessels are used for surveillance, pollution control and SAR, sometimes they support the danish police or customs by carrying their personel out to sea.

Regards
Göran