A HUGE OCTOPUS CLUNG stoically to the rock face, attempting to blend in with the surface. It was doing a good job until it was spotted.
The early spring water temperature was just about the same as we would have expected at home, at around 11°C, and I suspect that the octopus was torpid at this temperature. I know I was!
Either way, it made no attempt to make a dash for it with a blast of distracting ink, as others might have done, and it allowed me plenty of time with my camera to record its portrait.
Only its blinking eye betrayed that it was actually a living creature.
Octopuses, purple soft corals, orange-red scorpions, crimson sponges and precious few other fish species seem to constitute the full catalogue of life-forms in this backwater of the Adriatic.
Its the complex topography under the rugged cliffs of the islands that is the main draw for divers, with plenty of arches and tunnels to explore.
Theres only so much rock I can look at, which is why I was keen to drop onto the wreck of the mv Peltastis, known locally at the Grk (the Greek), because she was a small freighter of that nationality.
Just after New Year in 1960, Peltastis was voyaging with timber from southern Croatia to Italy when she fell victim to the sudden yet notorious 125mph winter wind called the Bura, or Bora. It turned the normally placid waters into a maelstrom.
The ship ran for cover, hugging the coastline, but to no avail. Trapped in the bottleneck made by the island of Krk and the mainland, she could not make it through the rough seas in the narrows towards Trieste, so the crew tried to anchor in the shelter of Krk.
Alas, the seabed there was made up of loose sand. Two anchors went down, but they dragged and failed to hold the ship. She was holed on a rock and foundered. All the crew made it to the lifeboat except for the captain, who went down with his ship.
We plunged off the aft deck of the Irma, Oxygene Croatias steel-hulled dive-boat, and sank through the gloom towards where the wreck lay.
It was what I call a very British experience. Most of my fellow-divers were from Sweden, so they too were accustomed to seeking out a wreck in the murk.
I was reminded of my first wreck dive off the South coast of England 30 years before and considered that, although the descent was similar, had that wreck been as intact as this one I might have been more enthused.
The Peltastis lies on an even keel at 32m to the seabed, so makes a perfect nitrox 32 dive. Halyards to the central mast are still in place. Winches sit where they were originally installed. Ventilator shafts still stand proud.
Only the wheelhouse has been extensively salvaged. The wooden hatch covers floated off long ago, and the cargo of timber drifted ashore somewhere, but the sides of the holds are home to countless scorpionfish that lounge around, waiting for an unsuspecting meal to come along.
Its a small ship, only 60m long, so its no challenge to swim the whole length from stern to prow.
We made our way to the propeller at the deepest part of the dive, noting the hole where the ship struck, now home for a large conger eel. We then headed back up through empty holds, past deck machinery and up to the forecastle.
Running out of no-stop time, we convened as a group at the base of the mast before wending our way carefully up to the top, where our downline was tied at 7m.
The serious photographers in the group wanted to do the dive again that day, because it seemed to offer so many photo-opportunities.
Towns with unpronounceable names spelt without any sign of a vowel, 101 spotty dogs, a national football team with shirts patterned in red and white checks, and a coastline so crowded with islands that the sea, protected thus from the wind, looks like a lake - thats all I knew about Croatia before I came.
Apart, that is, from the fact that before its independence from the
former Yugoslavia it was so starved of investment by the government in Belgrade that people used to take motoring holidays there and return with sorry tales of how their cars had broken on the rough roads.
Modern Croatia is making up for lost time with a 21st-century infrastructure and a stupendous feat of engineering that is the motorway between Zagreb and the coast, with its chain of long tunnels and viaducts.
Yet it still has quaint old Mediterranean towns with cobbled streets cramped with stone buildings, and wild mountainous wooded countryside, dotted with lakes, where wolves and brown bears still roam free. The Croatian Tourist Office calls it the Mediterranean as it used to be.
Many Croatians who once decided they would find better lives elsewhere are returning to the opportunities realised by this new national independence. Boris, Rick and Lara grew up in Johannesburg but, contrary to their parents, they felt that their own children would have a better future in the new Croatia than in South Africa, so they resettled back where they started. All speak English with colonial accents.
They own and operate the modern Oxygene Croatia Dive Centre in Crikvenica (Cr is pronounced like an English Ts) about two hours mainly motorway driving from Zagreb, itself only a two-hour flight from London.
Croatia is blessed with abundant rainfall, and we seemed to be doubly blessed during the week that I was there. It was quite chilly too, but Im told that in summer it can reach 40°C in the shade, with sea temperatures climbing to 26°C at times.
Its then a favourite haunt of German nudists, who love to set up camp on the endless number of discreet beaches set in the cliffs along the coast.
The water temperature during my week there was a less pleasurable 11°C, just the same as at home, and walking down the path from my hotel one morning reminded me of experiences white-water rafting, such was the torrent of rainwater pouring off the hillside.
Crikvenica is a small holiday resort on the coast of the mainland overlooking the channel that passes between it and the large island of Krk. As such, the sea conditions are incredibly well protected, apart from a strong southern wind, should it blow.
The surface of the water was as waxy as a calm lake and the dive centres boat travelled at a stately if sedate speed. The wreck of the Peltastis is only 20 minutes from the jetty.

GETTING THERE: Flights from the UK to Zagreb, Pula, Trieste, Ljubljana or Rijeka with Croatian Airlines. Excess baggage charges apply (allow £140 for 10kg return).
DIVING: Oxygene Croatia in Crikvenica offers up to 40% nitrox (continuous blending), www.oxygenediving.com. You will need a a Croatian diving licence, which costs around £12.
ACCOMMODATION: Theres a choice in Crikvenica, including the magnificent Therapia Hotel, an ersatz palace built on a hillside overlooking the water in the last days of the Austro-Hungarian Empire, and considerably updated since, with health spa and indoor/outdoor pools. The Balatura ethno hotel is converted from a farmhouse by another Croat back from living in Germany, where he made TV wildlife films. Oxygene Croatia also has some self-catering apartments.
MONEY: The kuna (about 8 to the pound)
HEALTH: There is a new 10-person hyperbaric facility at Crikvenica.
WHEN TO GO: April to October. Other periods may be available for group bookings. Drysuits are recommended before June.
FOR NON-DIVERS: White-water rafting, hiking, cycling, paragliding, day trips to Venice, Plitvice Lakes National Park
PRICES: John Bantin travelled at the invitation of Scubatravel Worldwide Holidays and Oxygene Croatia. A one-week holiday including diving in July costs £700-1100, including flights from London.
FURTHER INFORMATION: 020 8563 7979, gb.croatia.hr