Like many authors who try various careers before they become full-time writers, Yves Bonavero has an eclectic CV. In his case, however, you can't really see the writing replacing the other careers it probably wouldn't be as lucrative or as interesting.

French by birth and education, he came to England 30 years ago at the age of 23 and never left. He worked in the City of London for 14 years, ending as chief executive of a financial conglomerate, then left to spend more time with his family and pursue other interests.

One of these was to become an undergraduate at Oxford University, the same year as his oldest child Olivier. Here, he studied German and philosophy for three years while also running a film company. Now back working in finance, he's also found time to write his first novel.

The Mirror newspaper described Something in the Sea as "brilliantly creepy and worryingly enthralling", which is a pretty good assessment. As a psychological thriller, much of what transpires is left to your imagination.

The story is told in the first person by Terence, a London lawyer who is sailing around the Adriatic with his doctor wife Cathy and six-year-old daughter Lucy. After a nasty storm at sea which leaves them battered and bruised, their yacht limps into Dubrovnik harbour in the early morning.

A large motor-cruiser lands alongside and its wounded skipper, Kurt, comes aboard for medical treatment. He tells Cathy and Terence that there are two bodies on his boat and during the dark hours of the night recounts his rather sad and troubled life story. But is he a murderer? Let's just say that people can do unspeakable things to their kith and kin which have major ramifications years afterwards.

Had he come across characters like Terence and Kurt in real life?

"I'm smiling as I listen to your question," he replied, in a surprisingly strong French accent. "Sometimes some people who have just begun the book say, Well, I'm just reading your first chapter. Very gripping. Are you Terence?' And if I want to embarrass them I say Yes, of course I am,' and then wait for them to finish the plot." He stressed that both characters were fictitious. "But you don't get to my old age without having read a lot, met a lot of people and you draw consciously or unconsciously from that," he added.

For him, it's a book about how love can go wrong. "That can apply to marital love just as well as to parental love, and both of them can have nefarious side-effects, which people with the best intentions seem to be quite unaware of sometimes," he said. "I think it's also a book about the dichotomy of fate, destiny, pre-destination or determinism on the one hand and merits and desserts on the other."

It's also a damn good read, although quite frustrating, since the action stops and the book ends with a brilliantly written stream of consciousness from Terence, leaving you itching to know more.

Yves spent three very happy years at Harris Manchester College. "What I found fantastic in Oxford was that there were more than 100 libraries," he said. "As I happen to like books I was a very happy bunny." He also enjoyed tremendously the experience of being taught new things. "After 20 years in business, pontificating most of the time to other people about what they should be doing or thinking, I found it immensely refreshing to have some of the best brains in the country teaching me about interesting things, and that remains one of my best experiences ever."

Because of his other commitments, Yves only spent half the week at university, which meant he missed out on many traditional student pursuits. "My son was quite embarrassed when in our third year I had to confess to him that I hadn't been to a pub once. He insisted on taking me there and then."

I asked Yves what it was like studying at the same time as Olivier, who did German and French at Queen's College. "The German part of the curriculum was largely shared, which turned out to be a very positive experience for both of us," he replied. "We ended up a lot closer than when we started."

After achieving a first-class degree in 1999, Yves thought about doing a doctorate in philosophy, but his application was rejected. "I was reduced to the other side of my degree, which was literature, and that led me to write the book." It was a toss-up which language to use. "I was more familiar with nautical terms in English than in French, so I decided to write it in English," he said.

Given his work commitments, where does the book fit into his life? "It's my reward for all the rest of my hard work," he said. It's so rewarding, in fact, that he's writing another.

Something in the Sea is published by Bloomsbury at £10.99.