- Jul 2011
The offshore patrol vessel (OPV) is a naval fad at the current time. Most important navies have them in some form. As you mention, the admiralties/DoD, etc. are trying to shoe horn the patrol function along with mine countermeasures (MCM) capability, as well as search and rescue (SAR) and so on. Most of them seem to have a helo pad, but that is not for ASW.
Mine warfare has changed so much in the last couple of decades, that this approach to MCM seems ill advised. The more modern (but also very expensive) approach is with "mother ships" from which can be deployed unmanned subsea vehicles (USV) and other remotely controlled equipment such as surveillance for undersea fiber optics, or sensors of various kinds. The mother ship can also be used to support diving operations - either for MCM or otherwise. Trying to cram all that on a 1,600-2,000 ton ships is problematic.
I believe I saw somewhere that the Royal Netherlands Navy and Belgium are going toward a common design about twice the size of a usual OPV, but mostly for the MCM mission. Theirs are to be about 3,000 tons. I suppose such a ship could also perform patrol duties. The additional fad of different "mission modules" that can be fitted to some newer ships is sometimes cited.
This isn't to say that the OPV is not important. Drug smuggling, trafficking in immigrants and other human cargo, the lure of smuggling other contraband to avoid taxes and duties is always there for the criminal element. Fisheries protection and a visible statement of sovereignty are also both involved. Either a navy or a coast guard needs adequate vessels of this type. Most are not suited to the tasks of warships.
I think Australia is very concerned to keep budgets in balance (unlike the US) and Oz also has been having issues with naval retention as have other navies. Economy is currently in vogue.
The OPV concept itself is sound, but the 'mission module' concept is flawed. A patrol vessel can't be turned into an MCM or survey vessel simply by swapping out modules. The gear is too specialised and for MCM vessels the hull and machinery are specially adapted for low magnetic and acoustic signatures.