I DON’T know a single bloke of my generation who has never owned a divers’ watch and boasted about its ability to work 50, 100 or 250 metres under water.
Whether their only experience of life beneath the waves was dunking their head beneath the bubbles in the bath tub or swimming underwater at local swimming pool, a waterproof watch was the playground must-have when I was at school.
But these watches’ high pressure capabilities were nigh-on pointless, nonetheless.
There’s a sense that this might also be the case with the function of the factory-fitted options seen on the Jaguar XKR tested here.
With a gargling 503bhp supercharged, five-litre V8 nestled beneath its long, vented bonnet, and stunning pumped-up coupe dimensions penned by former Aston Martin design chief Ian Callum, it boasts all the same appeal of the standard XKR.
Look closely, though, and a road-hugging front splitter, pronounced duck tail spoiler and prominent brake cooling vents communicate that this car has been fitted with Jaguar’s optional Speed Pack.
Commanding a £3,500 premium over the standard XKR’s £77,950 list price, it sees the XKR’s speed limiter hiked up from 155mph to 174mph, the steering recalibrated to be less sensitive at high speeds and the addition of all those spoilers and vents to aid stability.
Given that no UK-based XKR owner was ever likely to get anywhere near the original 155mph limit, let alone the new 174mph one, it could be considered a rather costly list of additions.
It’s also, perhaps, about as necessary as a diving watch for an 11-year-old schoolboy living 50 miles from the nearest coastline.
For sheer visual impact, however, the Speed Pack turns the XKR’s wick up a few notches.
Despite being just four months from its first update since 2006, the current XK still looks as fresh as it did when the day it was unveiled, but the aggressive make-over only adds to it graceful yet muscular appearance.
And adding further to the more hardcore appearance of my test car was the Black Pack. Costing a further £500, and only available in conjunction with the Speed Pack, it comprises of gloss black window surrounds, front grilles and 20-inch alloys.
From inside the car none of the above really matters.
Despite the craned necks of pedestrians and fellow motorists, all I was aware of during my time with the XKR was its artful blend of luxury grand tourer and extremely potent sports coupe.
Once that supercharged V8 is awakened by a prod of a starter button which pulses red, mimicking a beating heart, all I wanted to do was sample its performance.
At genteel speeds comfort and refinement are the party pieces served up by the XKR, though.
There simply isn’t another coupe out there which can ride with such cosseting efficiency and cruise with such refinement, yet unleash such epic grunt when called upon.
For sheer day-to-day usability, the Jag easily has the edge over Porsche’s 911, despite an equally cramped excuse for rear seats.
Ease the throttle towards the carpet and that five-litre V8’s influence swells around you.
The sensation of being pushed along on the supercharged units surge of 461lb.ft. of torque and 503bhp consumes you like the sensation of sliding into a hot bath.
Jaguar claim that the XKR will hit 62mph in 4.8 seconds (with or without the Speed Pack, incidentally) and the silky smooth nature of the engine’s delivery gives its performance a lustrous polish.
There is character in the big coupe’s handling too.
The XKR’s not accurate or dynamic in the same way as a Porsche 911—it concedes a dose of intimacy through the steering and a chunk of agility to Stuttgart’s finest export—but there’s an old school brutishness to the way it wants to smear its broad rear tyres across the tarmac out of corners.
Hit the ‘dynamic mode’ button located on the gloss black centre console, from the civility of the leather lined interior, and the XKR can almost be driven on its throttle once the front end is hooked into a corner, the excellent ZF automatic gearbox holding gears loyally in manual mode.
Leaving the electronic aids in place seems a wise move in all but the broadest of race tracks, though. This is one big car with big grunt and the ability to scribe huge, arcing slides around corners.
There’s little doubting that Jaguar’s current range line-up is its best for decades and the XKR encapsulates its new found success thanks to a more youthful, performance oriented set of values.
Sure, its 23mpg fuel consumption, 292g/km CO2 emissions and the elevated 174mph top speed seen on the Speed Pack version tested here might not make it the most practical car in the range but it remains the best luxury coupe on sale today.
And, as pointless as that elevated top speed and aerodynamic addenda might be...it looks a damn sight better value than a divers’ watch.