Three miles long, a mile wide, the island is home to about 160 people, and one of the most remote populated parts of the British Isles you could imagine.
I've been going there for four years now and this particular ferry trip on the trusty Naomh Ciarn II was the worst I've seen, standing on the stern deck which tipped forward one moment, and backwards the next as water sloshed about in every direction.
As the roller-coaster ride came to a sudden end as we entered the harbour I felt compelled to show my nonchalance. "A bit bumpy today," I remarked to one woman returning from her regular grocery trip to the mainland. She looked at me like the soft Brit I am and suggested that maybe I should try it in December.
Maybe I won't. Cape, for me, is at its best out of winter but away from the summer when its self-catering houses and B&Bs fill up. For goodness sake, they even have a policeman on the island when it comes to August bank holiday.
No, Cape is an island best enjoyed alone, or as near to alone as you can get. That is its charm after all - while still being in these islands and driving on the left all the way I have never found another place on which you can truly claim to have got away from it all.
Until this year it has always been an early autumn trip with the heather dressing the hills in a priest's cloak of finest purple trimmed with the gold of drying bracken and gorse. So a late spring break, in May, seemed like going to a different place. As you approach you can make out little hill fires of bright yellow supplied by flowering gorse. Sea pinks thrive in the spring sunlight and over it all a blue haze which closer inspection finds to be bluebells in a profusion rarely found in England.
Now while those who make their money from the seasonal tide of tourists may argue with this, I would say, categorically, that there isn't much to do on Cape. Not much at all. A fair bit of the island is kept away from visitors behind barbed wire and warning notices. And after a couple of visits you will have seen the disused lighthouse, the view of Fastnet Rock, the two standing stones known as The Marriage Stones because of finger-sized hole right through one of them.
You will have had tea and cake in the shop at the north harbour, looked over the ruined 12th-century church of St Ciaran, wondered at the natural beauty of the south harbour, and maybe even have wandered down to look at the worm farm. For those from whom these surroundings breed restlessness there is a hostel which can offer courses in snorkelling, canoeing, kite flying, archery and other outdoor skills, and within a week you will easily have been to all the pubs on the island. Twice.
But that is its attraction. Every day this fragment of rock on the edge of the Atlantic looks different as the maritime weather sweeps across. And every day it offers a new view of what you thought was familiar. And even after a few years you find little bits of it you've never found before. This year it was a secluded cove, facing west over the Atlantic with a view of the ruined 14th-century O'Driscoll castle perched atop a rocky causeway.
Having praised the ability to do nothing here, I have to admit that on this last occasion Mrs Carter did decide to try something - a course in keeping goats, offered by a former sociology teacher from England, Ed Harper. Ed is typical of the few "blow-ins" who come to this island and stay, determined to get that Cape feeling all year round.
And then there are Chuck and Nell Kruger, American (via Switzerland), former teachers who now rent out a renovated stone house which is the southernmost inhabited building in the whole of Ireland. As for the island's native inhabitants, many speak Irish as their language of choice and this is one of the last of the areas in the country where children are brought up speaking it at home. Their English, meanwhile, is in the very heavily accented West Cork style. In other words it's a bit like listening to Bizet. Beautiful to hear, can't understand a word.
So what do you do while you're there? You walk. Firstly because, it being served by a passenger ferry you have left your car on the quayside at Baltimore (and when that's a hire car clocking up pounds 25 a day, that hurts). And secondly because the island is criss-crossed with paths although it's no use asking for a map where they are all neatly delineated. You have to find your own way round and ask where you are not sure.
But the rewards are great. The island is heaven for bird-watchers, being the first landfall for many migrants and a place where the odd lost rarity has a habit of turning up. And even without their strange half-a-binocular telescopes, the non-enthusiast can begin to appreciate the hobby. Not that we see many birds, what with three dogs on holiday with us - incidentally another great recommendation for Cape is that it has no sheep, so no worries for dog owners with over-enthusiastic charges.
But even with three furry friends, I've stood on the top of a cliff watching gannets diving for fish hundreds of feet below and I've been eye-to-eye with shearwaters and choughs, swooping upwards on the air currents rushing up the cliffs. Other wildlife to savour here includes seals, dolphins, a couple of years ago a basking shark and, if you're very lucky, you may see whales cruising past to the south.
Do all this and then, I'd be willing to put money on it, you start wondering if you could live here. How much the houses are? Could you do that job through the Internet? Is there something you could bring to the island economy that they just haven't thought about yet?
Well, if you can invent an easier way to the island through a force eight, you might just be able to.
Bob and Carolyn Carter and their dogs Alfie, Bob and Wilson paid pounds 198 return for the Fishguard-Rosslare crossing from on Stena Line (0990 70 70 70); this included pounds 50 for an overnight cabin. They then drove to West Cork and took the passenger ferry to Cape Clear.
Alternatives include a flight direct to Cork, for example from Gatwick on British Airways (0345 222 111), from Heathrow on Aer Lingus (0645 737 747) or from Stansted on Ryanair (0541 569 569).
The Carters paid IRpounds 200 per week at the Southernmost House (00 353 28 39157) on Cape Clear; rates are higher in peak summer. More information from the Cape Clear website: http://indigo.ie /cleire