What an Archer-class patrol-vessel successor should carry

What armament should a replacement for the Archer class carry?

A permanently fitted .50-calibre machine gun is the preferred minimum, giving it a weapon larger than a rifle-calibre machine gun.

The Archer-class comparison starts with small boats likened to Royal Navy-operated lifeboats. Their listed weapons are three general-purpose machine guns and provision for a 20 mm Oerlikon, with the cannon fitted for but not fitted. The proposed successor would carry a .50-calibre machine gun permanently. That would ensure something larger than a rifle-calibre machine gun was actually available.