It was August 1999, the day before full moon, and, so far as I am aware, the incredible sight I had just witnessed had never been photographed in cold waters before - Pennatula phosphorea and Funiculina quadrangularis corals, complete with gameter - tiny balls that include both eggs and sperm - nestling at the tops of their arms.
The gameter were clearly ready for release, because when we returned two days later they were gone - they had been dropped as the moon waxed and waned. Mission accomplished.
That was about 25m down a clay slope in Norways Sognefjord which, at 140 miles long, is the longest fjord in the world and at 1350m the deepest. The statistics speak for themselves, but on a human scale there are more magnificent fjords to explore, offering both stunning vistas and exceptional diving. The Sognefjord experience only whetted our appetites to explore Norways fjords further.
Ryfylke, in the south-west of the country, is an area consisting of thousands of islands and fjords, and the mild climate allows a splendid variety of plant and animal species to thrive there. Excavated by glaciers between 2 and 3 million years ago, these fjords might be smaller than Sognefjord but are among the most impressive in Europe.
After a good hour spent bumping about in our little inflatable, my muscles are stiff and aching. I have trouble jumping ashore as we berth on the Sinai Skerry in the Sandsfjord. We have chosen our spot carefully, at the narrowest part of the fjord. The chart indicates a depth of 240m, straight off the land - this place is ideal for wall-diving.
The weather is lovely, and for once we have plenty of time. As in most narrow stretches of water there is a strong current, but we have studied our tables; in an hour it will be ebb tide and calm water.
Once again, we are looking for deepwater corals. Under certain conditions, where cold water from the depths is forced towards the surface, it is possible to find species which do not normally thrive at diveable depths.
Time passes, but the current persists. On the other side of the fjord some locals are gathered on a quay. When we ask them when the tide turns, their answer leaves us open-mouthed. The direction of the current is constant here, they say - it flows outwards!
The explanation is simple. A number of rivers drain into the Saudafjord and the Hylsfjord further inland, and the fresh water must be carried off. It runs towards the sea on top of the heavier salt water.
After talking it over, we conclude that the current is not likely to go very deep, and I decide to check out conditions further down. I put on my gear and crawl down like a crab, holding on to the sea tangle. Eight metres down, I notice a sharp delineation in the water. There is no more current below it, and the visibility is almost the best I have ever seen.
Four metres further down and the gentle slope gives way to a vertical drop. For a short minute I float, feeling the suction from what seems to be a bottomless abyss. Then I head back up to report to the others.
Wall diving is most enjoyable when the visibility is good, and, where large amounts of fresh water combine with often-strong currents, there is likely to be luxuriant life on the walls. It is not unusual to come across species from greater depths, and the diversity is generally richer than on a flat bottom.
Like mountaineers, divers can always find a wall to match their level of proficiency in the fjords, though good buoyancy control is necessary even where you can follow it down to the bottom. When diving on the deep ones, experience is required.
Before undertaking such dives, for instance, you should have considered and trained in what to do if your BC punctures, or your drysuit zipper bursts.
I need to be in complete balance, both mentally and with respect to my equipment, to enjoy such a dive. If it becomes a struggle against negative buoyancy or other elements, the time might as well have been spent above the surface.
My two companions are anxious to get into the water, and soon were all crawling down the gently sloping rock face. As I let myself float out from the rock 12m down, I get a feeling rarely experienced by divers - I feel dizzy! I can see the rock reaching 30 to 40m below me, as I dump air and drop slowly into the unknown.
I can see the others grinning into their DVs - this is really something!
Terje chooses to stop at 35m, while Erling and I continue to 40m. The good visibility makes it easy to stay in contact, and, as I roll over to signal OK to Terje, I catch sight of the surface and get a momentary sinking sensation as I realise that I am hovering in open water, 200m above the bottom.
We slide along the wall. Big sponge fans, sea cucumbers and numerous other species cling to the rocks, but no corals. Below us are clusters of sponges, looking like people sticking their heads out from behind rocks to check whats going on.

We can see at least 30m down before the light gets too faint. Had there been any corals down there, we would have been unable to reach them.
Every now and then a fish pops up from the darkness to look at us, and I feel a little envious when I see how effortlessly it glides into the depths. What is hiding down there
The biology of the fjords is diverse, and every spot has its specialities. Piked dogfish, or sharks, skate and catfish are common here. For macro photographers nudibranchs, anemones and shrimps of all sorts are among species they are sure to observe.
Lobsters thrive, although unlike the crabs and scallops that are found in large numbers, divers are not allowed to catch them. You could find yourself fined£400 and have your gear and, if you have one, your boat, impounded.
Way too soon the dive is over. Decompression is fast. The water is comfortable and life abundant. We take a couple of fjord crabs back with us, and on the boat gather round the chart. Perhaps the deep-sea corals thrive better on the other side of the strait
The Lysefjord is the best-known fjord in Ryfylke, famous for its almost vertical cliffs. Its Pulpit Rock and the Kjerag Wall, which rises vertically for more than 900m, have become famous, not only in Norway but also abroad.
There is nowhere like it, and certainly no Norwegian fjord compares with the Lysefjord and its environs for smooth, vertical surfaces, because this is the only area in which the bedrock consists almost entirely of a mixture of homogeneous granite and gneiss.
The narrow sill fjord has cut its way several kilometres into the mountains, and though at its mouth the water is only 20m deep, further in it is more than 400m to the fjord bed.
From its highest peak to the seabed is a good 1500m. The cleverest mountaineers might be able to scale the highest cliffs here, but no matter how well-equipped we divers are, we can only hope to scratch the surface of these submarine mountain wilds.
Its an early autumn day, and the sun is shining on the polished rock face of the Lysefjord, speckled with green trees and bushes which have found subsistence in the many cracks left here by the ice.
We are out for pleasure, to check the biology of the area, and perhaps to get some pictures of marine species we have not seen before. Our boat glides slowly over the glassy surface.
The scenery is so spectacular that we need time to take it all in.
Ahead, Pulpit Rock hangs over the fjord, 600m above our heads. People standing near the edge of this angular structure look as small as sandhoppers from where we are.
Tramp Hole is a 10m-wide cleft that turns sharply in towards the mountain. Legend has it that boat tramps hid from the law here after a series of thefts. The head of the hole is screened off from the fjord, and it is almost as if we were on a little mountain lake.
The echo-sounder shows 60m. Had visibility been good, we might have explored part of the cleft, but silica algae have coloured the upper 10m of the water greenish-white, like pea soup.
Visibility will be better further down, where lack of natural light makes it impossible for the algae to survive, but we decide to save this spot for winter, when viz is normally good for several months on end.
We move on. Mooring is not easy, but eventually we manage it between two projections of the rock, the mountain hanging above our heads, the Kjerag Wall before us. The echo-sounder now shows 155m.
The dive turns out to be tough. The vertical plane along which we dive is completely smooth and only a few anemones and shellfish have been able to make themselves fast.
Today, for some reason, I feel downright scared as I swim through the unfathomable darkness, and, as diving is something I do for pleasure, I tell Erling I want to stop. He nods, and before long were back in the boat.
Now I want contact with the bottom. On the opposite side of the fjord is a small, sandy beach under a towering, dark rock. We tumble into the water again and make a controlled descent along the sandy slope. This dive turns out to be a more pleasant experience.
We find three big mud sea anemones with shrimps standing motionless in a circle around them, as if in adoration. Large edible crabs are everywhere, mainly females that are here to spawn.
At the sill of the Lysefjord, Erling makes a final dive. I stay in the boat, enjoying a cup of coffee in the sunshine. A boat chugs past, the tourists waving and pointing as Erling breaks the surface. Excited beyond belief, he is talking of thousands of sea cucumbers in every colour of the rainbow, but right now Im more comfortable above the surface.
The anchor is hauled aboard, and we head for home. In the Hogsfjord we nearly run into a whale, coming up right in front of our boat.
It is probably as scared as us, blowing out before it vanishes back into the deep. Just how many secrets do the deep fjords of Ryfylke hide