The UK had four lightly armed and armoured Offshore Patrol Vessels highly suitable for Norway to Gibraltar service on Fisheries Protection, Maritime patrol and SAR operations. These are known as Batch Ones. These are due to be 'replaced' by Batch Twos - battle-hardened and with enhanced combat versatility. The MoD were pretending that these were a replacement for the Batch ones but in fact they're destined for Gibraltar, Bahrain, the Falklands and the Caribbean to plug a Frigate-hole in the Fleet. The four Batch Ones were due to be scrapped or sold out of the Service, and indeed one of them, HMS Severn, has already gone.
However, our esteemed and respected Sea Lords hadn't expected Brexit, and the need for enhanced patrol and protection of the UK's new 200 mile Exclusive Economic Zone from 2020.
It's not just protecting our waters against Dutch and Spanish pirate trawlers stealing our fish. Since the dear old Nimrod ("Ten thousand rivets flying in close formation"*) went our near-coastal ASW capability has been compromised - and with the integrity of our underwater comms cables ever more essential to national security, we need to be extra vigilant. A combination of long-endurance drones and response vessels with RM boarding parties and RIB fast launch and recovery kit for both constabulary duties and escorting foreign warships making passage in and over our waters mean the Batch Ones will have a use for many years yet.