Whenever Spanish vessels (either from the Armada Española, the Guardia Civil, or a piratical fisherman chancing his luck) intrudes upon British Gibraltar Territorial Waters, I am mindful of this last mention of the Gibraltar Guard Ship in the parliamentary record.
Gibraltar Guard Ship
HC Deb 15 April 2003 vol 404 cc52-3W
Mr. Jenkin To ask the Secretary of State for Defence which Royal Navy vessel last carried out the duty of Gibraltar Guard Ship; and which warship is on station carrying out those duties. 
Mr. Ingram The Royal Navy presence in Gibraltar is provided by The Gibraltar Squadron. The Squadron usually comprises two patrol vessels. This is appropriate to the current assessment of requirements. Currently, on a temporary basis, there are four patrol craft in Gibraltar whilst the task is transferred to vessels reassigned from Northern Ireland. HMS Ranger and HMS Trumpeter are the outgoing patrol craft, HMS Scimitar and HMS Sabre are the incoming patrol craft. No frigate or destroyer is deployed as a Gibraltar Guard Ship.
Note the key element of this reply. “No frigate or destroyer is deployed as a Gibraltar Guard Ship.” Oh, how they must have rubbed their hands with glee in Madrid!
Is it any wonder why, 10-years later, illegal incursions in BGTW occur… and occur again… and again… and with seeming impunity?
A politely-worded diplomatic note from the FCO (“You are being naughty. Please stop. If you don’t stop then we will write you another letter.”) is barely worth the paper they it is written on. Occasional fluffing of feathers by Royal Marine RIBs occurs on those rare occasions (subject to predictable protest from Madrid) that a RN submarine occupies the Z Berth. This is patently insufficient.
As far back as 1798, Nelson wrote of his operations in the Mediterranean, “Was I to die this moment, ‘Want of Frigates’ would be found stamped on my heart.” How little appears to have changed! The Royal Navy is decommissioning frigates and destroyers faster than they can build replacements – even presupposing the political will exists in Whitehall to replace them on a like-for-like basis.
One thing is certain, and that is that displays of weakness only encourage the aggressor. Spain is encouraged by Britain’s perceived weakness. Madrid is encouraged by the weak-kneed response of Whitehall to illegal incursions. Diplomatic note follows diplomatic note. Yet this is insufficient to prevent the illegal incursions. Mild hurumphing from the FCO is not getting the job done. A guard ship might.