SAILING: Time on the Ocean: A Voyage from Cape Horn to Cape TownBy Theo Dorgan, New Island, 298pp. €15.99

'ARE BOATS really meant to do this?" the poet, writer and sailor Theo Dorgan asked at the outset of his book Sailing for Home, which recounted a voyage from Antigua to Kinsale undertaken in 2001. It was the first time that Dorgan, a relative newcomer then to sailing, had attempted a passage of such duration, and his book sparkled with the novelties that greeted him at every turn.

During that voyage he also discovered, and recounted with great skill and patience, the beguiling emptiness of a long sea journey and how dreams dreamed at sea seem to stand alone. The ocean for Dorgan had become nothing less than “a place I can call, in absolute simplicity, home”.

It is a much more assured Dorgan who, in 2006, flies to southern Chile and joins the crew of Pelagic Australis, a 21m aluminium single-mast yacht, for the 6,500km voyage to Cape Town. It is May – winter in the southern hemisphere – and the ocean between the two capes is cold, dangerous and unforgiving.

This voyage holds a unique attraction for Dorgan. His great-grandmother died in childbirth off Cape Horn and was buried at sea there. But for the presence of a wet nurse on that passage home to Ireland from Australia his grandfather might well not have survived. Now Dorgan rounds Cape Horn, four generations later: “And here I am, I whisper, here I am, named for your son but unhoped for, I’m sure of it, in your last moments.”

Along with seven others of various nationalities, none of whom he knows, Dorgan is paying for this expedition, which is a training exercise as well as an epic adventure. At the end of 30 days and more, before they reach Cape Town, they will sit an exam on board for the Yachtmaster theory qualification. The skipper, Steve, will be the judge of whether these aspirant skippers are worthy candidates. Steve’s two close sailing buddies, the watch leaders, bring the total crew to 11.

The pitfalls of sailing 6,500km on a 21m boat with 10 people youve never met before – on Dorgan’s previous long voyage there were only four – cannot be exaggerated. In addition to the normal tensions, the crew have paid a lot of money for this experience and often don’t take too kindly to being bawled out by the skipper. The skipper must inspire respect and not be seen to pick on the weaker crew members. Dorgan, who admits he bridles under authority, bites his lip and keeps his head down.

As every sailor knows, you come home from the mildest jaunt in the Med with a dozen bruises; in the wild Southern Ocean the physical attrition is savage. “I don’t know how I’ll stand up to really bad weather . . . I worry about letting people down.” And yet Dorgan transmits the pure joy of being out alone in the midst of the emptiest ocean, an elation that transcends the problems of on-board politics. Dorgan’s spirit soars – and with it the reader’s.

A brief stop in the Falklands, a barren, lost place, reveals the only possible motive for going to war over such a spot: oil. East of the Falklands, from Stanley to Tristan da Cunha, will be a long and demanding slog, often motor sailing, in an ocean of few if any other vessels.

As he sails out across the bottom of the world, Dorgan builds up the human tensions in step with the worsening weather. Here are brave and wonderful descriptions of a storm you never want to get into. Sustained by a “dour will to endure”, the sailor comes off his watch, battered and sore, and crawls into his bunk, where the poet begins to dream the boat he is imbedded in, “somewhere deep in the ocean . . . a good boat making headway in a heavy sea”.

Dorgan makes the physical and mental challenge seem easy, but it was far from it. He filed regular pieces during the voyage for The Irish Timesbut now admits that he deliberately downplayed the height of the sea and the strength of the wind. No point in worrying loved ones at home, after all.

Time on the Oceanwill be relished by all sailors, to be sure. But it will also give hours of pleasure to anyone who appreciates superb writing and for whom a tale of the human spirit pitted against raw nature is irresistible.

Peter Cunningham's most recent novel is Capital Sins