A riddle in the wake of the Childers classic

A submarine snaring of a Clogherhead fishing vessel, the Sharelga. Swoops on the gunrunning vessels, Claudia and the Marita Ann. A quick flick through Tom MacGinty's recent history of naval patrols in Irish territorial waters, and one wonders why some of the factual material hasn't been jumped on by fiction writers before now.

Over 90 years after it was first published, Erskine Childers's The Riddle of the Sands is still regarded as the best known spy thriller in these parts with a maritime theme. It has been described as a forerunner of Le Carre and Graham Greene in its evocation of the paranoia and intrigue leading up to the first World War. Its principal characters have a school boy innocence: Carruthers is "pressganged" for the yacht, Dulcibella, because he speaks perfect German, and the skipper, his, old Oxford friend, Arthur Davies, likes to shoot ducks.

What lends The Riddle of the Sands authenticity is the author's knowledge of small boat sailing. By the time he came to write it, Childers had not only served as and artillery driver in the Boer War, but had also made six voyages to the Baltic. He knew those mudflats, thick fogs, murky channels and tiny harbours. It would be another decade before he would sail his yacht Asgard off to try a bit of illicit arms trafficking himself.

Bjorn Larsson, a Swedish sailor, does not claim any first hand experience of the latter subject but he has cruised extensively in Baltic waters and has written a book which has already been compared to the Childers masterpiece. Ulf, the principal character, lives on a 31 foot boat, Rustica, in a Danish harbour. One moonless night during an electricity cut, he guides in a visiting Finnish catamaran. The skipper, Pekka, is exhausted, nervous, and has a traumatised woman on board. Before the customs arrive, he gives Ulf his logbook. He vanishes before dawn, pursued by a man named MacDuff.

Mysterious references to a "Celtic ring" arouse Ulf's curiosity, as does Pekka's recorded itinerary - twice across the North Sea and into Scottish and Irish waters. The log mentions druids, ritual sacrifice, the festival of Samhain, and a passage into Lough Swilly with the same MacDuff under cover of darkness. It is only when Ulf hears of the Finn's gruesome death later on that his curiosity is really aroused by which time he has convinced a student friend, Torben, to set sail with him on a hazardous winter crossing in Pekka's wake to Scotland.

As a device for engaging the landbound reader, the character of Torben works well. He has no sailing experience; in his world, a sheet is something one sleeps under, port an alcoholic drink. He gets seasick, but bears it with good humour. "Don't you think that your hero Hornblower would have been pleased with you?" he quips when Ulf takes in a reef in a gale in four minutes flat.

During the voyage, they are shadowed by an unnamed fishing boat, and find themselves near victims of deliberate sabotage when canal lock gates burst open and trap their boat. They have made considerable passage and had a few more frights when they discover that the "Celtic ring" is not made up of peace loving druids in white robes with golden sickles in their leather belts. The "sickles" have been exchanged for machine guns, the robes for bullet proof vests.

As a plot, the Celtic theme is a little hard to digest; but at least the author does rely on contemporary accounts, like that of Tim Pat Coogan, for his references to the IRA. Simple descriptions of life at sea, such as the numbness of night watch - raw air, eyes fixed on compass, mind in an emotional vacuum - restore one's faith just when patience is a little stretched, and the text combines suspense and intrigue with a distinct smack of salt in the air.

The publishers say that a film company has started work, and translations have been issued in France and Germany. With this first English edition, one could do worse than while away a few hours on a summer passage to Scotland. Even if it does induce nightmares about "Neptune's staircase" - that flight of eight locks on the Caledonian Canal... {CORRECTION} 97051500073