Just been watching this on C5, it does not inspire any confidence in the modern Royal Navy!
For those that did not see it, a British Destroyer HMS Manchester (Type 42), came across a 'Go-Fast' which was abandoned.
Essentially they are fibre glass boats, with big engines for drug running.
It was decided that this boat posed a 'major' hazard to international shipping, not sure why it was a boat about 12/15 feet long. Any tanker would have just ploughed through it.
So the Captain ordered it to be Sunk.
The Destroyer:

The Go-Fast (not exact but about this size)

They let the 'Big Gun' blast about 15 rounds at it, its a 4.5 inch gun, 55-calibre. 15 rounds, about a foot long, failed to sink it :-?
So they sent out a Helicopter, with a heavy machine gun, and a feking big sniper rifle. That failed to sink it. :-?
So the Destroyer moved in closer, and let rip the gating gun type thing, again that failed to destroy it. :-?
In the end, they had get a saw out, cut through it, fill it with petrol, set it alight and capsize it

When they did finally catch a drug running boat (a wooden fishing boat capable of 4 knots) it had to escort it back to Colombia (250 miles away) which took 4 days!
No wonder drug running is a big business, its almost impossible to get sunk, and if your caught your chauffeured home