This is drifting off the topic a bit but ...
First off Britain can't end. It's a geographic term not a nation. The United Kingdom on the other hand probably will cease to exist as a nation state in due course but not through devolution but rather through absorbtion into a European nation (an inevitable end run of the way the European Common Market has developed into the European Union and continues to gradually leach power from national governments to the European parliament and administration)
Secondly, the role of the Royal Navy
has changed dramatically since it's heyday as the worlds largest and greatest. The UK no longer has an empire to administer, there is no longer a single
significant potential enemy with large scale naval forces to defend against.
During the cold war period the primary role of the RN was anti-submarine and land forces support in the European theatre in the event of a Soviet invasion. By the 1980's the RN barely had the ability to prosecute an action at long range (the Falklands/Malvinas) something which at the end of WWII it was extremely well equipped to do. Today such an action would be virtually impossible.
The planning trend since the melt down of the Soviet threat has envisioned that the primary role of the UK military now and in the future is in so called "peace keeping" actions and anti-terrorist operations largely within the European theatre. There is a somewhat limited role for naval operations in these actions other than in supporting the ground forces.
With the decimation of manufacturing industries in the UK since the 1950's, the loss of all the economic benefits of empire (the rump that is left is just a minor burden) and the high financial cost of EU membership
(the UK is a net financial contributor whatever the other arguable benfits of membership
may be) the UK can no longer afford a substantial military and certainly cannot justify a substantial navy
The UK military is now in crisis due to its involvement in US led actions in Iraq and Afganistan. The UK is only involved in these arenas because senior political leaders do not want to admit that the UK is no longer a world power. The nation, in truth, no longer has the industrial capacity, financial strength or will amongst the electorate to play with the big boys but how long we will have to wait for a Prime Minister willing to give up "special relationship" meetings with the US President, forgo the UN Security
Council veto and other such vestigial relics of the great days when the UK was a genuine world power remains to be seen.
The plain truth of the matter is that the UK can no longer afford standing military forces (Army, Navy and Air) of significant size in world terms. The economy would benefit tremendously from an acceptance of the reality of the situation by our senior politicans. That reality is partially reflected in the reduction in size of our military but not in the role that the politicians expect it to perform.
One aspect of the stupidity of this disjointed thinking is that the RN would be far more useful if it had more smaller
vessels. A handful of frigates, a couple of modest aircraft carriers, one decent assault ship and a hatful of less capable ones are of limited use in policing roles. If we start from the self evident facts that there is no longer a large naval power to face off against, that if such a power evolved in the future then only the US has the industrial and financial capacity to combat it and that the primary role of the UK military in the future is in neo-military policing actions then the RN needs to return, in effect, to the days of "gunboat diplomacy".
By this I mean that the RN in it's current
and future role would be better served by having fewer large ships of the frigate/destroyer type and more smaller patrol vessels such as the River Class (although ideally a new design, slightly larger and a good deal faster carrying a bigger complement of Marines, a permanent helicopter and capable of worldwide deployment).
To expand on this further, instead of two new dedicated aircraft carriers the RN would have more use for several combined function land assualt / air support vessels similar to HMS Ocean but capable of deploying a half squadron of VTOL air defence/ground attack aircraft as well as support and attack helicopters and troops. In truth, the two new aircraft carriers, when they are finally delivered, are likely to be used in this role rather than a purely air support role although they will require additional assets in support due to the failure to think "out of the box" when they were designed.
Finally, it's highly questionable whether the UK actually needs a submarine force capable of delivering strategic nuclear weapons. Once again, economically the country cannot afford them. The desire amongst senior politicians to replace Trident once again stems from an unwillingness to accept that the country is no longer a world power. Having submarine based nukes means they can play hardball with the big boys but the fact is we're punching well above our weight. A small force of conventionally armed fleet submarines may be justified for their ability to conduct intelligence and covert operations.
The bottom line is that, as a country, we cannot afford to continue with the illusion that we are a world power. Any large scale military action is going to be primarily prosecuted by either the US military or a combined European force. The UK, since we are stuck with being in the EU, should of course contribute to the latter. Whether we should be so keen to get involved with US led military actions is a political debate I don't want to go into hereabouts!
To get back to the topical point, having set out the background, if the RN scrapped a couple more frigates the money
saved would easily finance the construction and deployment of half a dozen or more extended capability patrol vessels equipped with a small helicopter, several RIBs and a useful force of Royal Marines. One or two such vessels stationed in the Gulf of Aden with suitable RoE would put an end to the yacht piracy
problem for starters!