THE CURRENT POINT WAS JUST ahead of me, round the corner on the reef wall. I could see a large bunch of silvery dogtooth tuna swimming hard nearby.
I picked my way carefully from coral outcrop to outcrop, ducking out of the oncoming flow until I reached the apex of the corner, where I stuck my current hook into a bit of firm substrate and remained floating free of the coral.
Five grey reef sharks played out an aquatic ballet in the rush of water. A long line of barracuda, not in their usual compact swirl, swam Indian-file.
Four huge trevallies that had chosen the same route as me were surprised to come across a strange air-bubbling creature hovering at the end of a line, and were forced to move out into the blue water. A little parrotfish flapped momentarily beside me before it gave up and allowed itself to be swept away.
None of the other divers from my boat had joined me. I guessed they had found something better to watch, but as it was I enjoyed the show for about 30 minutes before unhooking, and allowing myself to be taken along at the mercy of the current.
It dropped as soon as I got back round the corner, and I was reduced to 15 minutes of hard finning to catch up with everyone else.
About as far south as you can travel in the waters off the coast of Sudan without entering Eritrean territory lies a sun-blasted island, little more than a patch of sand. Its called Dahrat Abid.
And at another similar island nearby, Barra Musa Kebir, the unfortunate crew of an Italian submarine suffered an enforced stay during World War Two, after colliding with the island and sinking their vessel. The wreck now lies too deep for any diver.
Both Dahrat Abid and Barra Musa Kebir are actually the tops of mighty pillars that drop from the surface sheer-sided into many hundreds of metres of water. With nothing to commend them but sand and a small amount of scrub, their only riches are to be found beneath the surface.
Dahrat Abid has a small submerged plateau swept by ocean currents and home to lush soft corals and a Red Sea reef that few divers have touched.
Dahrat Abid has a special place in my memory, from the days when I was the lucky (some would say unlucky) dive guide on a southern Red Sea expedition, way back in 1992.
I remember surfacing near the island after a dive with my charges, all Italians, to find that no liveaboard or inflatable in sight, only the open ocean.
This gave rise to rather a lot of disappointment at the time, and was the result of a technical problem with the boat. It returned three hours later with the problem resolved but, of course,
we didnt know it was going to do that while we were bobbing in the ocean.

NEVERTHELESS, PREPARING to dive at the same place 17 years later gave me a slightly insecure feeling.
This time, however, I was travelling aboard Royal Evolution, a vessel built to international passenger-vessel safety standards, rather than on some local vessel pressed into service for the long journey to such a remote spot.
Building a liveaboard of this type requires all sorts of high standards to be met. The quality of the steel is examined, and welds are X-rayed by independent surveyors during construction.
The British-built twin 38-litre diesel engines have to meet international requirements, and are mounted such that little vibration is felt through the steel hull when they are running.
The effect is quite eerie, because in anything less than a rough sea its quite hard to decide if the vessel is underway or not without looking out of a window or over the rail.
A raft of safety devices far in excess of those normally encountered on any other Red Sea safari boat must be carried in order to conform to international safety requirements.
When you embark on a long journey such as the one we made from Port Ghalib near Marsa Alam in southern Egypt and head this far south, these things become more important than the quality of the carpet or brass fittings.
Entering Sudanese waters, and passing the wreck of a Lebanese freighter sitting atop Elba Reef, was a timely reminder of the significance of such safety precautions.
This vessel is built to do the job and, yes, it was waiting for us when we surfaced after a dive at Dahrat Abid.

THE SUARKIN ARCHIPELAGO is dotted with tiny islands, but there is so much sea between them that many seabirds gratefully made use of our vessel as somewhere to roost and rest their wings.
Under water, there are also habilis (reefs that dont break the surface), and although the marine life around these is no different to that at familiar sites further north in southern Egypt, theres just a lot more of it!
Big yellow-tail barracuda maintain their position as a diver approaches, rather than making a quick exit; spotted sweetlips hang about in vast numbers; horse-eye jacks rival chevron barracuda in their attempts to form up their legions in an orderly manner; schools of silver dog-tooth tuna cruise urgently by; and giant sweetlips, not often seen further north and looking altogether like the grandpas of fishes, sit around in pairs on the reef being cleaned. On one occasion, a huge black manta ray tantalised us from afar.
There seemed to be a resident hawksbill turtle on every dive and, if busy feasting on the soft corals, they were oblivious to the divers watching them. This provided lots of interesting photo-opportunities, and some animal action for those with video cameras.
As the reefs, habilis and islands of southern Sudan are actually these fingers of rock that stick up from the seabed hundreds of metres below, they create an obstruction to the gentle flow of water that makes up the prevailing current along the west side of the Red Sea. The water has to speed up to get round them, or over the submarine reef plateaus that often protrude at either end.
This causes quite strong localised currents at times. Many larger pelagic species are drawn to these currents, which also cause the corals to grow prolifically - not only in quantity, but in a huge variety of different species that grow side by side.
We dived at places such as Protector Reef and Penzance Reef, the habili at Dahrat Qab and some other habilis that have yet to be named. It was the same story everywhere; virgin coral and masses of fish of all types.
We also enjoyed the regular company of a few young silky sharks that followed the boat for a time, and gave all the divers quite exciting safety stops under the hull.
They added an edge to night dives, when they became less timid. Their close passes provided heart-stopping moments for divers swimming through darkness back to the safety of the boat.

GREY REEF SHARKS TURNED UP ON cue to thrill us further once we made our way back north to Shaab Rumi and Sanganeb. They zipped around the south reef plateau at about 25m deep, hoping for a handout of food, and weaving among the massed divers trying to get good pictures of them.
It was here that we also saw massive bumphead parrotfish in greater numbers. The sharp cracking noises as these ugly creatures violently head-butted each other in a quest for dominance were quite disturbing.
There was a lot of procreation going on among the reef fishes at this time (May) and everything seemed to be chasing everything else.
An unfortunate titan triggerfish decided to bite a Napoleon wrasse that it felt had trespassed into its nesting territory, and paid dearly for this foolhardiness. The Napoleon simply grabbed it and shook it like a terrier with a rat, leaving its lifeless body for the grey reef sharks to come and tidy away.
We had to undergo formalities in Port Sudan before we could start diving. This meant that we headed south before working our way back north to Egypt, diving on the way.
Of course, we didnt miss the chance to dive the WW2 wreck of the Umbria on Wingate Reef, just outside Port Sudan. Ive been lucky enough to dive this wreck often. That noted diver Hans Hass always called it the worlds best diveable shipwreck, and Im still inclined to agree.
Umbrias crew scuttled the ship after being escorted into Port Sudan by the Royal Navy on suspicion of carrying arms to Eritrea. The captain heard on his personal radio that Italy had entered the war, and decided to deny the Allies his cargo of bombs and guns. Under the guise of doing a fire drill, he got his crew to open the seacocks.
The big passenger/cargo ship went down undamaged, and with all its equipment and cargo intact. It lies on its side with its starboard-side lifeboat davits breaking the surface at low water, a watery time capsule from 1940.
I took the opportunity to record the few areas of the wreck I had omitted to cover on previous visits, including details of the ships engine-room workshop, with its lathes and milling machines; a wheelbarrow near the galley; and the captains private bath and lavatory.
I took care not to allow the crazy angle of everything to disorientate me.

THE UMBRIA MAKES A GOOD playground for divers, and its relatively easy diving, but that was not why we had come. It was the reefs south of Port Sudan that drew us, and we headed for the most southerly point in our itinerary, Dahrat Abid, before working our way back north again, diving every few hours on the way.
I can confirm that, other than in the immediate vicinity of Port Sudan, we encountered no other diving safari vessels until we got back to Egypt.
It was like diving in the Red Sea back in the old days.
Most of Royal Evolutions passengers were obsessed with seeing sharks under water, and spent a lot of time in the blue hoping for sightings of schools of elusive scalloped hammerheads.
Im sorry to say that the worlds shark populations are so depleted now that I felt the generally low number of sightings was indicative of the way things had changed recently.
It wasnt until near the end of the trip, as we headed back towards Egypt, when we stopped at Habili Ghadban, far north of Port Sudan, that the passengers were rewarded with the sight of hammerheads everywhere.
It was the one dive I had decided to miss, in order to start work on this report! Habili Ghadban translates as Extremely Angry Reef - and I was.
There had been a strong current of the sort on which hammerheads like to surf, using their curiously shaped heads as wings, but by the time we went in for another dive the current had changed. The hammerheads were still there, but stayed wraith-like out in the blue.
They simply moved out further from the reef if any of us tried to swim out to them. Bad luck for my camera and me!
As some sort of consolation prize, Yasser, the boats owner, and I had a momentary encounter with a great hammerhead at Abu Fanadir (not to be confused with a reef of a similar name in Egypt). The shark came up over the shoulder of the reef plateau, saw us and made a quick about-turn.
It really was something of a beast, with its massive dorsal fin, and made the scalloped hammerheads wed seen look puny by comparison. Grey reef sharks passed by at the margins too, along with a couple of little whitetip reef sharks.

FINALLY, AS WE ENTERED Egyptian waters, we were blessed with a dive that was attended by three longimanus, the long-handed shark or oceanic whitetip.
These ocean rovers have learned to follow commercial shipping up through the Red Sea, because they spend their time in shallow waters looking for anything suitable to eat, and kitchen waste is commonly thrown over the side of freighters. Royal Evolution is such a big steel vessel that its passage rings the dinner-bell for these graceful animals, gliding like aeroplanes on their long pectoral fins.
Its not all about sharks, however.
The often current-swept reefs are resplendent in masses of colourful soft corals.
Big grouper lurk under table corals, masses of surgeonfish form an ever-present curtain across the backdrop, and all manner of different types of jack hustle along the reef wall that is formed right up to within a few metres of the surface.
Im sure it wont be long before we see other suitably equipped vessels venturing south to the waters of the southern Sudan.

FACTFILE
GETTING THERE: Fly from the UK to Marsa Alam
DIVING & ACCOMMODATION:John Bantin travelled at the invitation of Yasser el Moafi, owner of Royal Evolution, and Scuba Travel (www.scuba.co.uk). Dive guides were Hisham Ayad, Simon Gardener and Ahmed Daood.
WHEN TO GO: Spring or autumn are the best times for diving. Summers are extremely hot and it can be stormy in winter, though still warm
PRICES: A two-week trip to the Sudan on Royal Evolution, including return flights, costs around £2450. You can buy an excess-baggage allowance of 10kg with Thomson Airways for around £140 return. Visas for two Egyptian entries and one Sudanese entry plus permits cost around 360 euros. There may be a fuel surcharge.