IT HAD BEEN A WHILE SINCE I HAD INDULGED IN A TYPICAL-CLUB DIVING EXPEDITION. Not the regular site stuff, but the kind of thing where you take the RIB somewhere a little further afield.
First thing I needed was a typical club boat, and for that Humber lent me the typical club boat, a 5.8m Destroyer.
The ensemble was completed with a 90hp Honda four-stroke outboard, Star M55DSC radio and a Lowrance LMS240 combined echo-sounder/GPS/chart-plotter with the latest Navionics digital chart cartridges.
I had a longstanding ambition to try some of the sites up the Sound of Mull and round the corner, the sort of locations you wonder about while on a regular trip to the area, after diving the Hispania and the Rondo. It wouldnt be exploring in the real sense, but all the diving was new to me and my friends.
I also had an invitation from Caithness Diving Club to sample some of its hardly dived sites, and sketch a local wreck for a Wreck Tour. Caithness is the bit of Scotland that sticks out to the north-east. Divers drive through it intent on reaching Scapa Flow, but few ever stop to dive there.
So we would spend a few days at Lochaline, diving the Sound of Mull and further afield, then move on to Thurso at the north-eastern tip of Scotland. Different, adventurous, and all well within the capability of the average dive club.

We head up the Sound of Mull at 25 knots. My cautious first-day plans have already been abandoned.
The previous evening we had been eaten alive by midges while cutting holes in the Humbers shiny blue console to fit the instruments. With a new and unfamiliar boat, I had intended a shakedown day at local sites, but Phil Robertson of Lochaline Dive Centre reckoned we would have only a couple of calm days and should take advantage of them.
Plans had been revised. Provided we were happy with the boat while running up the sound, we would head further afield.
The boat handles like a dream and everything works, so we push on. I want to dive the Tapti, a 4411 ton steamship wrecked at the south end of Coll in 1951, but we dont know whether one 90 litre tank of fuel will get us there and back. We consider filling up at Tobermory, but the fuel station is closed Sunday afternoon.
I pull Moir and Crawfords Argyll Shipwrecks from my drybag and begin comparing wreck positions to the digital chart. We settle on the Aurania, an 8499 ton liner converted to a troopship, torpedoed and wrecked at Caliach Point on the west of Mull, and a dive new to all of us. Its on much the same route but a good 10 miles closer than the Tapti.
All we have are the plan and numbers in the guidebook. Its a well-broken wreck on a rocky seabed, and I am cautiously pessimistic about finding it!
We get some beautiful traces on the echo-sounder. Wreckage or rocks The chart-plotter clinches it - being able to see our exact position on a detailed chart and compare it to the diagram in the book decides which group of echoes we should dive.
I land on wreckage and claw my way upcurrent and offshore, with about 2 knots running along the coast.
We soon find the bows, and first one enormous winch then another, anchors and chain spread between them, pollack holding station above. Then its a zigzag drift back to the boilers and debris from the engine.
What isnt covered in fine red kelp is home to impressively sized anemones and dead mens fingers. Ballan and cuckoo wrasse play tag as we duck in and out of back-eddies to retrace our route.
Next day we are again heading for the south end of Coll and the Tapti, with a fresh tank of fuel and a couple of jerry-cans just in case. Keeping the speed down to 20 knots, the Honda is far more economical -35 nautical miles from Lochaline and five-eighths of the main tank remains on the gauge.
Phil Robertson has given us some numbers, and with the plan in Argyll Shipwrecks and the amazing plotter display we soon have a good echo. Our shot lands just aft of the boilers.
Protruding wreckage is covered in healthy yellow dead mens fingers and small anemones. The wreck has collapsed to starboard, bows out to sea, leaving the keel against the rocks and the deck laid out flat on the sand. It is easy to navigate past the remains of the superstructure and mast to the bow. Further into the current, the bow proves to be home to a thick colony of plumose anemones.
We are already getting used to the casual convenience of the chart-plotter. For our second dive I leaf through the book and notice that the wreck of the Arnold is almost next door, so we move the cursor to the appropriate point on the chart, then drop a shot on a likely-looking echo.
We just miss the rudder-post and a section of keel. I follow the shaft forward to the engine and boilers. There is less wreckage than on the Tapti and it fizzles out somewhere in the middle of the forward holds. The bow section must be somewhere nearby, but I dont have time to find it.
Driving back, I casually follow my nose into the Sound of Mull. The Lowrance is on split-screen between echo and chart. I can hug the shoreline as close as I like, with plenty of warning of shallow reefs. The echo tracks beautifully, even at 20 knots.
Nearing Lochaline, we cross the wreck of the Shuna, a yellow buoy marking the superstructure. I put the Humber into a tight circle over it, staying on the plane. The Lowrance retains a good echo, wreck rising 8m from a 30m seabed. I am impressed.
The weather deteriorates, and diving is restricted to sheltered sites in the Sound of Mull. We dive some standard wrecks and some acclaimed but less-dived walls.
The petrol from the Tapti trip lasts the next morning out to the Shuna and on to the pier at Tobermory, where we fill up. We just make it, burning vapour without having to crack the jerry-cans. Cruising at 20 knots the Humber and Honda have managed 85 miles plus loitering on location from 90 litres, carrying five divers, my rebreather and eight cylinders.
With a rougher sea, rain and spray, some weaknesses in the boat and equipment start to show up. Bouncing on a wave, heavy kit stowed forward demolishes the lid of the bow locker.
The RIB also takes on water over the transom far too easily, not just at the cut-out for the outboard but over the transom itself. Then the bilge pump packs up. Its OK at speed with the elephant trunk down, but stop to kit up and we are soon ankle-deep in water. We continue to take on water even while the divers are down.
The Lowrance sounder/plotter performs to perfection but the Star radio first starts to flash though channels and behave unpredictably, then dies. It isnt up to an open console in a dive-boat. Even when working we had found the controls too small and close together to use in a moving boat, and impossible with dive gloves on. Shouldnt someone start making radios as waterproof as Lowrance does its GPS and echo-sounders
The drive from Lochaline to Thurso takes seven hours, including 90 minutes at Fort William to sort out overheating trailer hubs dripping molten grease. The brake mechanism has grounded somewhere, causing the brakes to bind, possibly on a slip, maybe on the ferry at Coran, or perhaps just on a rut in the road. We sort out the jammed mechanism, slacken the cable and pack fresh grease into the bearings.

Heading out of Scrabster for Ushat Head, the cliffs are spectacular. Stacks, caves, cuts and overhanging horizontal ledges, seabirds everywhere - it holds promise of some interesting underwater scenery.
The sea is not particularly big, but very mixed up with waves reflecting from the cliffs and crossing the incoming waves. With six of us now in the boat, the low transom and failed bilge pump is worrying, but we dive anyway. At least with divers out of the boat we can drive round and clear the water.
Picking a dive site is easy. We head out from the cliffs guided by the digital chart and watch the echo-sounder until we detect an irregular slope at 25m. Apparently anywhere along this stretch of coast is good.
Past 20m I can just pick out enormous square shapes on the seabed below, seemingly arranged in a regular pattern. My eyes and mind say wreckage - could we, by some fantastic coincidence, have landed on top of an undiscovered wreck
The feeling lasts only moments, as my eyes adjust to the dark green twilight. Now I can make out the huge blocks of stone naturally eroded into these surprisingly regular shapes. Should I theorise about ruins from an ancient pre-Ice-Age civilisation
The current is just mild enough to allow us to meander among the blocks without having to drift with an SMB. Everywhere is plastered in huge yellow dead mens fingers. I cant remember when I last saw such a dense and uniform carpet of marine life, especially on such an unusual relief.
Caithness offers some of the most exposed coastline and, in the Pentland Firth, some of the strongest currents off mainland Britain. However, it has two complementary coasts, one facing north and the other south-east. The weather has to be extremely unpleasant before there are no sheltered options to dive.
A couple of days later we join the club to dive from a small fishing harbour facing almost south into the Moray Firth. Its called Dunbeath. Only a few hundred metres offshore is the wreck of a 10,191 ton tanker hit by torpedo in 1940.
The Gretafield caught fire, was abandoned at sea, then drifted into the bay before it grounded and broke up.
The wreck lies well smashed on a rock and sand seabed at 12m, though much of the wreckage is shallower. With normally clear water, in the summer this wreck can be swamped with kelp. At the end of May, when we are diving, is pretty much as late in the year as the locals bother with.
The shot is next to an enormous boiler. With the engine at the stern, this turns out to be the most interesting area of the wreck. There are six boilers and the remains of a four-cylinder steam engine connected by a short length of shaft to the stern.
A more challenging wreck for our Wreck Tour is the Ashbury, a 3000 ton steamship that ran aground in Togue Bay in 1944.
We trailer the boat west to a small harbour at Skerray and encounter a slight problem. The slip is sufficiently flat that we need to use a rope on the trailer, but I have lost the key to the ball hitch. Our solution is to unbolt the towbar from my car and lower it down the slip with the boat!
Among a scattering of rocks and islands, the sea is flat and sheltered. We have fun playing James Bond with the boat, navigating by the chart-plotter and echo-sounder as we zoom through narrow channels.
Wreckage is now well distributed along the rocks. Even without the wreck it would be a good dive, as there is plenty of colourful marine life beneath overhanging ledges. I have fun sketching it, coming up only after 90 minutes, according to plan. After a short break and a sandwich I am back down to finish my sketch. I then mind the boat while the others dive a canyon which tunnels right through the end of Eilean Losal.
When it comes to cuts and caves, a spectacular location is the Geo of Sclaites. This cut goes 100m back into the cliffs at Duncansby Head, wide enough to drive the Humber into and with room to turn round at the end.
Seabirds rest on ledges above us, but seem happy with our presence, so we dont get dive-bombed.
From the back and sides of the geo, narrow caves lead deeper into the cliffs. Marine life is a mixture of kelp, small anemones and tunicates, giving way to sponges and then bare walls as we work further back. The sea outside is moderate, but with the geo to funnel the waves in and the caves funnelling further, there is a powerful surge between the narrow walls.
We finish with a day at Stroma island, partly because it is sheltered from a strong south-easterly and partly because the slip at John OGroats is steep enough to launch without having to unbolt my towbar again!
The remains of the Bettina Danica are well broken among shallow kelp-filled gullies. Its a 1354 ton freighter driven onto the rocks by a storm in 1994. Half the stern is wedged against the cliffs, hatch covers perched high on the clifftop. Under water the wreckage is sparse, but there are some nice overhangs where the marine life is colourful and not overwhelmed by kelp.
At the opposite end of Stroma we make a shallow drift through a seal colony tucked in behind Swilkie Point. This early in the season, the seals are inquisitive but not playful.
Next day I drop the boat off at Humbers factory in Hull. As one of the workers unbolts my towbar I learn that all Humbers hull moulds have been re-engineered to give a transom the same height as the tubes. We had been diving one of the last hulls made with the lower transom. There is also an option to have an open bulkhead across the bow, avoiding the fragile bow locker wed managed to shatter.
Over 10 days diving the Honda 90 burned£240-worth of petrol. What we had enjoyed was being able to talk without having to shout while driving at full speed.
One of our divers even fell asleep right next to the engine, not waking as I started and stopped it to keep on station.
The Star radio was unsuitable for a RIB, but we were all impressed by the Lowrance LMS240 Echo Sounder/GPS/Chart Plotter. The digital chart modules from Navionics were brilliant, so good that in areas listed as uncharted in the Admiralty catalogue, and hence without detail on the digital chart, we felt lost without it.

Launching the RIB from the ferry slip at Lochaline. Ask the ferry crew first, and make sure you dont get in the way.
The Lowrance LMS240 combined echo-sounder/ GPS/chart-plotter and the Star M55DSC radio
Swimming through a winch on the bow of the Aurania
Steering quadrant on the Arnold
the top of a piston from the Gretafields four-cylinder steam engine
part of the Taptis steel superstructure
Preparing to dive on the Bettina Danica. Half its stern is wedged under the cliff, with wreckage stretching away to the south-east
A crab defends its patch of sand just off the Gretafield
LOCHALINE DIVE CENTRE: 01967 421627, www.lochalinedivecentre.co.uk
CAITHNESS DIVING CLUB: Chairman Ian Mackay, 01955 606106, www.caithnessdivingclub.com; wreck information: Davy Carter, 01955 603739, www.hellsmouth.com
HUMBER: 01482 226100, www.diveribs.com
HONDA MARINE: 01753 590500, www.honda.co.uk
SILVA UK (Lowrance and Star): 01506 406227, email: info@silva.ltd.uk
NAVIONICS UK: 01752 204735, www.navionics.co.uk