This involved the young Macneil running a lobster fishing operation that required him to get up every Monday at 5am to check his pots in time to get any occupants to market before school.
He said: "By the time I was in S3 we were operating 120 pots. On good weeks we were making £700."
Now at the helm of the thriving Witherby Publishing Group, Mr Macneil said he was an exceptionally determined 14-year-old, with no apparent exaggeration.
The enterprising youngster subsequently showed his mettle by going to sea aged 16 on a cargo ship out of Liverpool.
Before starting the business that developed into Witherby, Mr Macneil enjoyed a successful career in the merchant marine, which included travelling the seven seas on gas carriers and working on a floating production vessel in the North Sea. Between watches he studied for his officer's qualifications.
When we meet at Witherby's Livingston HQ, Mr Macneil is preparing to head east to spend a day on a bulk carrier negotiating the Great Barrier Reef in Australia, on which many boats have foundered. This will be followed by 48 hours on a super tanker sailing from Kuala Lumpur in Malaysia to Singapore.
Learning acquired in the process will be incorporated in books the company plans to publish.
Such attention to detail prompted the 41-year-old to spend 10 days with a veteran ice master in Canada, Patrick Toomey, learning about the pitfalls involved in navigating areas like the Arctic.
Mr Macneil said: "It's all about keeping the boat moving.He really was the number one guy. I spent ten days with him and it was a fantastic learning experience."
The company says its Ice Navigation Manual "brings much of what is relevant for the Officer or Master on a merchant vessel, operating in ice conditions, to a single publication".
There is a boys' own air to Mr Macneil's story that may seem at odds with the prosaic West Lothian location from which he leads the company.
Since 2008, it has operated out of an industrial estate in what was once known as Silicon Glen. The area became the graveyard of the dreams of economic development experts after computer firms retrenched in the 1990s.
However, Mr Macneil is presiding over one of the untold success stories of Scottish business.
The company has carved out a profitable niche in a maritime industry that has been a beneficiary and driver of globalisation.
Some 85% of Witherby's orders come from export markets. The company sells to 110 countries, led by Singapore.
On a tour of the facility the scale of the business soon becomes apparent. Behind a smart office suite, Witherby has a warehouse that can hold 400,000 books.
These include products like pocket safety guides designed to be easily understood by crew members whose first language is not English. The company employs a team of well-educated mums to proof read.
He said: "If they can't understand it, a reader is not going to be able to."
Sales are booming. The Response to Marine Oil Spills second edition, with a section on the Deepwater Horizon incident in the Gulf of Mexico, sold more than 2000 copies on the first day. It has a £95 cover price.
Mr Macneil expects to post turnover of £4.5m in the year to May and to grow that to £6m the next year. The company employs 32 people in Livingston with another 10 in India.
The seafarer has come a long way for someone who went into business by accident.
The origins of the group lie in a learning tool that Mr Macneil developed after getting frustrated by some of the material he used in his nautical studies. This featured thousands of multiple choice questions.
Soon after launching the tool, in 1998, Mr Macneil was achieving £5000 monthly sales.
With a small team of employees, he went on to develop a portfolio of similar products. Mr Macneil moved into publishing in 2001 with a book called Ship Stability Mates/ Masters though his Seamanship International business.
He decided to focus on content after taking time out to think about the future in 2004 with his wife Kat.
Ms Heathcote had big jobs with the likes of the Wood Mackenzie energy consultancy.
He said: "She's got a great strategic brain, fantastic editorial skills. I've got creative thinking, the inventor bit and technical knowledge of what's happening in the industry."
The same year the company took the first steps towards forging the union with a much bigger rival that was to help it make a quantum leap. This involved a joint venture with London-based Witherby, one of the oldest names in British publishing.
Founded in 1740, Witherby was well known for publishing titles on subjects like cargo shipping.
The joint venture, which published 12 titles, paved the way for the merging of the businesses. The merger was negotiated in 2007.
Following the death of a friend at a young age in that year, Mr Macneil and Ms Heathcote decided the enlarged business had to be based in Scotland rather than London.
The Witherbys accepted, leading to a merger of equals which has delivered huge benefits.
The enlarged company publishes more than 400 titles and can access the client list built up by seven generations of Witherbys. Last year, the remaining shareholders from the Witherby family were bought out, in a seven figure deal.
Mr Macneil believes the company is set for sustained growth in the burgeoning maritime market.
Regulatory change is creating demand for new titles in areas such as sulphur in fuel.
He is confident the company can continue to flourish in international markets without leaving Scotland. Livingston is well placed for employees across Scotland and provides easy access to airports.
Mr Macneil displays a determination the firm should remain special that seems appropriate given his unconventional career.
This is epitomised by the company's policy of awarding employees an abridged version of a book called Small Giants: Companies That Choose To Be Great Instead Of Big, by Bo Burlingham.
Other benefits include a Wellbeing Plan under which Witherby supplies and fits winter tyres for employees' cars.
With plans to stick around at the company for another 30 years or more, the former boy fisherman does not subscribe to the get-rich-quick view of business.
He complained: "Youngsters are being taught that you should build something just to sell it.
"Success is too often measured by people exiting."