There's little in the culinary arena that excites debate quite like sushi. Everyone (excluding the barbarians who won't eat it, and the Philistines who insist it all tastes the same) knows the one place you simply have to go to for the most delectable raw fish on the planet — a claim usually accompanied by a whispered assurance that the chef is genuinely Japanese rather than some vaguely Asian prop furnished with a large knife and a male nurse's outfit.

Cape Town's awash with the best sushi restaurants ever — rarely a week goes by without heartfelt assurance from somebody that pristine nirvana has been discovered.

A good run

Sushi Zone in Observatory, Blowfish in Blouberg, Wakame in Moullie Point, Willoughby's at the Waterfront — they all receive gushing reviews on a regular basis, along with dozens of other less salubrious outlets that suggest food poisoning is likely to come as a complimentary extra with the ginger and wasabi.

I've eaten at all four of the above, and all four are generally excellent. Sushi Zone, despite a dreadful name, is a hidden gem amongst the bare feet and tye-dye of Obs; Blowfish is a beacon of culture in a culinary desert; Wakame is awfully cool (and usually boasts more silicon per square metre than anywhere outside of Clifton 4th in December); and the fish at Willoughby's is uniformly excellent — if you want fresh fish, this is your preferred stop.

The price is right

But over the last few weeks, I've been running a comparative analysis on Cape Town's two inner-city contenders for cut-price sushi customers.

Partly, it's to rid my system of an ill-advised raw fish order last month (Zurich International Airport's departure lounge is not the place to try octopus sashimi at nine o'clock on a Wednesday night), and partly it's because, given the fact that my bond appears to grow in sympathy with the Zimbabwean dollar, good quality sushi at half price is a strong attraction.

And so too the two contenders: Beluga and Tank. Beluga, the Green Point kid that hit the big time, found fame and favour with international magazines and grinning celebs and then fell victim to its own success, is now very much on the up again.

Tank, just up the road in the Cape Quarter, opened with a similar bang — and the spurious claim, if memory serves, that the kitchen included Japan's seventh-ranked sushi chef (who knew there were rankings?) — hit the big time, and is now trying to scramble back into the spotlight after experiencing its own dip in fortune.

Quality versus time

In the economy stakes, Beluga strikes an early blow, offering half-price sushi every day before 7pm, and all day on Sundays. Tank hits back with the rather modest 5pm-7pm on a Friday. And that's the chief downfall at Tank — everyone rocks up 15 minutes before orders have to be in, which means you'll be lucky to eat before 8pm.

And for all the theatrics of slicing up fish and turning rice into ornate caviar-dusted parcels, I refuse to believe that preparing sushi takes long enough to justify the wait at Tank.

But what does justify it, is the quality. I have not had quite such rich, buttery, obscenely indulgent salmon as that which finally arrived, amidst some excellent tuna, and assorted Japanese oddities that blur in the wake of the salmon. Great value at full price — astounding value when halved.

So can Beluga compete? Not in the salmon category — although theirs is excellent, as is the tuna. The two fish are your standard gauge for sushi in South Africa, and Beluga scores impressively on both counts.

For the love of wasabi

Their wasabi isn't the most searing — I have a masochistic love of feeling like someone's rubbed the inside of my nose with industrial sandpaper when I eat wasabi — but the whole package gets a very firm nod and ceremonial bow.

Enough to beat Tank? On the sushi alone — not quite.

The price moves them level, however, Beluga's R99, 24-piece platter is roaringly good value.

Service nudges Beluga ahead (Tank charged full price for a couple of half-price items, and you're in for the long haul if you order after 6.30pm), and a final flourish seals Tank's narrow defeat — the bill at Beluga comes with a small bowl of heavenly jelly beans. I'm happy to pick up the tab at Beluga, but that means the beans are mine, and mine alone!

And that's enough to have me back at Beluga on a regular basis (a cracking wine list, and a kilogram of prawns for R99, doesn't hurt either); but despite the tortoise model service, Tank will probably see me again fairly soon as well (half-price cocktails to complement the fish doesn't hurt).

Two more than capable sushi restaurants, then, where you can cheerfully stuff yourself for under a hundred rand: when times are hard in Cape Town, raw fish is the way to go.

Tank: Cape Quarter, 72 Waterkant Street, Green Point, contact them on +27 21 419 0007. Beluga: The Foundry, Prestwich Street, Green Point, Cape Town; contact them on +27 21 418 2948. All reviews unannounced, and paid for in full.