I think this was published in the journal of the Volunteer Marine Rescue Western Australia.
I decided to day-sail up the WA coast, keeping behind the reef and anchoring every night. I replaced the trampolines and rigging of my 11 year-old Seawind 24 catamaran, Nulla Nulla, and I put aboard some bedding, a change of clothing and a couple of packets of muesli, and I sailed from Rockingham to Geraldton, speeding along from waypoint to waypoint, dodging the reefs, eyes on the GPS screen.
This civilised sailing - flat water, a good sleep every night - ended at Port Gregory, where the Zuytdorp Cliffs begin. Port Gregory is 30 miles north of Geraldton. From Geraldton to Steep Point, which is the south entrance to Shark Bay, there are no sheltering reefs and the stretch of 140 miles from Port Gregory to Steep Point would have to be done without a stop. The contrast with the previous easy sailing could hardly be greater: this is one of the world's most inhospitable coasts.
Except at Kalbarri and at a hook in the coastline 17 miles south of Steep Point called Zuytdorp Point, the Zuytdorp Cliffs form a continuous limestone wall, 60 metres high. Vertical or overhanging, the cliffs rise directly out of deep water. Owing to the depth, there is no surf; the eternal south west swell of the Indian Ocean simply collides with the cliff. The reflected swell is seen and felt for ten or fifteen miles out at sea. In the earlier, inshore, part of my trip one of my options, in extremis, was to swim ashore. That option is not available off the cliffs as there is nowhere to land. Even if there were, it would mean death from exposure and thirst.
The only human habitation is at Kalbarri. It couldn't be considered as a place to stop since negotiating the Kalbarri bar requires local knowledge and I heard nothing good about it. Anyway, it is still 100 miles from Shark Bay. What I had to do was clear: depart Port Gregory with a favourable forecast and sail direct to Steep Point - just like any offshore yacht.
Nulla Nulla commonly zips along at 7 to 10 knots but to average such speeds for 140 miles would require a favourable wind over an unlikely length of time and distance. At a more realistic 5 knot average, 140 miles would take 28 hours. Given some wind, it seemed the trip could be done with one night at sea.
Nulla Nulla has no self steering. I did think about it but cats don't work well with wind vanes (owing to the instability of their apparent wind) and there would be a power supply problem for an electric model. Generally the helm is neutral and fairly stable and with shock cords attached to the tiller, the boat will hold course for many minutes. This gives time to potter around or make lunch but not, obviously, to sleep. For the Zuytdorp leg it would be a good idea to have crew.
I asked my wife if she would like to go cruising in Shark Bay. She was aware that a Seawind 24, with its one foot draft, would be ideal for Shark Bay, so she said she would indeed like. What was the catch? The catch was that the cruise was the other side of an off-shore overnighter. Fran was equally aware that the Seawind 24 was not designed for ocean passages. Still, she agreed and it came to pass one fine, breezy morning at the end of May, that I saw her waving from the beach as I lay at anchor in front of the Geraldton Yacht Club.
It was a matter of course that we were not about to go anywhere before Fran had organised the food department. But the provisioning for this trip actually needs to be much more generous than its 140 mile length would indicate. The moment you turn the corner at Steep Point, you are instantly in your cruising paradise - but you are not near a shop. If you wish to cast off the wet weather gear and don the snorkel and flippers to enjoy what you came for, you need to have stocked up back in Geraldton. Water, also, is not available in Shark Bay outside the few centres of habitation. We had to load up.
If you have a cat and you don't want to turn it into a dog, you must keep it light. Even more vital: for safe sailing, the weight you do have must be kept out of the ends of the hulls. This requirement for stowage in the hull middles is in conflict with the need to live there - to sit, cook, etc in the roomiest part. A catamaran's long, skinny hulls pose a fundamental interior design difficulty and on the Seawind 24, the middle is the only place that there is any living space other than in the tunnels forward which serve as bunks.
To the extent weight does have to be spread out from the hull middles it is preferable to place it aft. When multis somersault it is usually by burying a bow and tripping. The buoyancy of the bows must be maintained. The Seawind 24 has self-draining anchor lockers in the bows in violation of this principle but because anchors are such ugly things, and because room on Nulla Nulla is so limited, I have always kept my anchors there. I should say that there is only five metres of chain with floating rope rodes and with nothing else whatever in the forward third of each hull. (Since then, I lashed two plastic milk crates in front of the mast and have taken to keeping the anchors in them. Apart from better weight distribution, the anchors are handier.)
In a sheltered waters you don't need to be too fussy about sea keeping qualities, but off the Zuytdorp Cliffs it would be sensible to have everything going for you, especially in a diminutive boat like mine. Accordingly, we set out with water containers under our feet and the hulls slightly down at the transoms.
Winds began flukey then picked up in the afternoon to get us into Port Gregory before dark. The anchorage is well protected. The wind blew hard from the south all night and had we kept going, we'd have been half way to Shark Bay by morning. However we had been told that Port Gregory was an attractive spot and besides, it was Fran's first boat trip in years.
Freshly showered (When would we get another shower?) and with last minute grocery purchases from the Port Gregory caravan park, we weighed anchor about 10 am with a pleasant southwester and a forecast of variable winds. The Zuytdorp Cliffs form a slightly concave line on the chart so a straight course with both endpoints close to shore means most of the trip is about 10 miles off. Such an offing, or more, is desirable from such a fearsome shore and to reduce the discomfort of the reflected swell.
The breeze weakened and we spent an irritating afternoon trying to keep the spinnaker full. At sunset we were abeam of Kalbarri, slopping along at one or two knots. With the main sheet tensioned hard we dawdled on a weak easterly for the next six hours. The main flogged but it is fully battened so it does not crack.
At midnight Fran took over and I squirmed into bed. But there was to be no sleep for me. Clouds had been building slowly in the west obscuring the stars and it now fell calm. Fran told me we were going to be hit by a squall. I lay wide awake. Wallop! We were off and racing on a wild westerly. The genoa sheet got free and before it was recaptured it had wiped out the 27 meg aerial. (It was mounted in a stupid place. Well, I didn't put it there.) That was the distress radio out of action. Now we really did have to get it right.
A whale surfaced, mere yards away, a black bulk in the darkness. It snorted a few times and moved off. Our dagger boards were up, of course.
I got into bed again but the wind was gusting and variable. Another squall. The wind was hard from the west then moderate from the south and for a while we drove at five knots, reefed, wing on wing, steering by stars showing from behind the cloud masses. We shook out the reef, the wind shifted east and we began to speed up: 7, 8, 9 knots.
Blazing phosphorescent wakes streamed out in the starlight. I sent Fran to bed and hunched down under the starboard dodger, glancing from stars to compass to GPS and occasionally touching the tiller. The speed rose to 10-11 knots in the gusts with the traveller out and the mainsheet slack to absorb any sudden pressure. It was a long watch but by dawn we'd passed the halfway mark.
Under a slightly lighter breeze we set the traveller and strapped down the main to convert every gust to speed. Fran took over with 7 to 11 knots showing on the GPS, foaming wakes and a rock steady tiller. We had had monohulls before and she had never seen such sailing.
The wind died around midday and we motored through the afternoon. Because of the mild conditions we closed the coast for a good look at the cliffs in the afternoon sunlight. They are sheer, vertical rock and where there is a slot, the swells collide in the confined space and the spray explodes almost to the top of the cliffs. A couple of miles off, where we were, the ocean was a lumpy confusion of swells in all directions.
I was surprised by the performance of the outboard motor and had to revise my opinion of it. It is mounted on the centre console between the hulls. I had seldom used it and was somewhat derisive of it, presuming that it would cavitate (suck air) in a sea. It did not. I have since used it in more severe conditions; it never cavitates.
We motored around Steep Point in deepening dusk and crossed the bar by the light of the stars and a sliver of new moon in the west. This can a dangerous place but conditions were mild. We had our moments when there seemed to be white water all the way across where the large scale chart said there should be 4m depth, but we found a gap in the surf and motored into peaceful South Passage.
We used the GPS to navigate a few miles to Sheltered Bay and in the morning awoke to find ourselves in limpid water over sand. Our Shark Bay cruise had begun.