Surely common sense has to prevail and whilst there is a place for patrol craft than that place must surely be coastal waters where shelter is readily available, fuel, stores and provisions. Would a larger, self sustaining craft be better suited with a decent gun,the ability to operate and store a helicopter plus be able to operate a smaller craft for boardings, inspections.
The Spanish are at present giving us the finger with our nice little 8 ton patrol boats with their GPMG main armament and no doubt other interested nations are monitoring our response to these incursions with great interest.
Going back to the thrust of this issue, can it be suggested the the modern navy is loosing sight of the differences between our frigates and the destroyer. Why not go back to the old 2000+ ton type frigates which were fully independent and capable of operating anywhere in the World and in any sea conditions. The type 23 frigate certainly looks like an amazing vessel, but at nearly 5000 tons they are a big ship filled with lots of very expensive goodies. Keep them but for the like of Somalia, the West Indies, the West Coast of Africa and even UK waters, perhaps a much smaller frigate is a better option?