The headline is misleading as I believe it is the UK government, and its policies through the years that is making a mockery of the Royal Navy. Russia is just taking advantage of it.
Russia's 'shadow fleet' makes mockery of UK naval power
Few things provoke British politicians into fits of rage more than mention of Russia’s "shadow fleet." Yet last week’s impotent tracking of Russian tankers in the English Channel illustrates that Britain doesn’t have the means to do much about it.
On 9 April, two Russian "shadow" oil tankers were escorted through the channel by a Russian navy frigate armed with all manner of weapons, including anti-ship missiles. In response, the Royal Navy could only muster an auxiliary fuel tanker to follow it helplessly. The Daily Telegraph reported on this heroic operation from the deck of a 40-foot fishing boat following in the tanker’s wake.
A regular pattern is forming in which the Royal Navy deploys vessels that are overmatched by better armed Russian naval escorts.
https://responsiblestatecraft.org/iran-war-gas-prices/