At a price of 152 pence per share the company was launched with a value of £125.5m, but by early March the shares had risen to 212p, an increase of 40% in just three months that valued the company at a hefty £175 million.

So those people with a few spare pounds in their back pocket and faith in the future of the £2bn a year UK marine leisure industry could have done a lot worse than chancing a flutter on Raymarine in those three months.

But with financial experts continually preaching the merits of diversifying our investment portfolios, are there any other options available to those willing to invest in our industry via the stockmarket?

The answer is yes, and probably more than you imagined.

At the last count there were five quoted companies whose activities are focused on the UK leisure marine business, plus a number of others such as Chemring and Vosper Thorneycroft which can offer a limited degree of exposure.

The most recent arrival prior to Raymarine was RingProp Plc, which joined the LSE's AIM market for smaller, higher risk companies in November 2002.

RingProp's business model is based on the design and marketing of a ringed propeller that, it claims, offers not only superior performance characteristics but also reduces the chances of injury in the event of an impact with persons or wildlife in the water.

Despite its short trading history RingProp has had an interesting time on the market.

Floated at an initial price of 130p the shares went on to hit an all-time high of 410 pence barely 12 months later following a recommendation on an online share-tip site.

"It came completely out of the blue, " commented RingProp finance director Giselle Sweet-Escott, "and with nearly three quarters of our shares locked in with long term investors it didn't take too many buyers to squeeze our share price up to those extraordinary levels. The actual effect on the business was zero. As the share price has no effect on the amounts of cash available to a company, it was just business as usual."

Fund raising RingProp completed a second round of fund raising in February 2005, raising £3 million for product development, sales and marketing and working capital requirements.

As a result the share price has dropped to a more sustainable 190p.

Following the departure of former chief executive Don Hoult at the end of 2004 the company has since appointed Gary Mullins, formerly the managing director of Chemring Plc's worldwide marine businesses, to take his place, and in its most recent trading statement RingProp looked forward to making substantial progress in 2005.

For those perhaps more interested in events than engineering, AIM-listed Clipper Ventures Plc offers a very different entry point into the marine business.

Owner of the rights to the Clipper Round the World Yacht Race and the 5 Oceans single handed Round the World yacht race, Clipper Ventures has also offered its long term investors something of a bumpy ride.

The original shares were placed at 42.25p back in October 1999, but the peak was just short of 80p in June 2000. Jeremy Knight, Clipper Ventures' finance director, attributes this to the "dot. com effect" that resulted from the company's ownership at that time of a telecoms business, since spun off into the independently quoted Offshore Telecom Plc.

After falling as low as 10p the shares are currently priced around 22p and Knight considers the business to be fundamentally undervalued.

"The nature of our business gives us a 2-year business cycle, " he pointed out in an interview recently. "Despite a turnaround in the business over the past two years the actual profits will not show in the accounts until April 2006, and the City has yet to recognise the positive aspects of our long-term outlook."

Less glamorous, but perhaps more profitable for its shareholders, is the rather lower profile Sutton Harbour Holdings.

Based in Plymouth the company offers investors exposure to maritime property via its ownership of Sutton Harbour Marina and a leading role in the regeneration projects taking place on the Plymouth waterfront.

Fisheries interests The company also has interests in the fisheries business and, in 2000, bought Plymouth City Airport and subsequently formed Air Southwest. Also quoted on AIM, the shares increased in value slowly but consistently from 2000 to the end of 2003, but since then have risen from around 80p to their current all-time high of 185p.

The company admits that "the growing success of the airline" may well have been a driving factor here, but the increasing popularity of waterfront property and economic growth in the South West may also have played a part.

The junior market for companies seeking a trading facility for their shares is OFEX, characterised by a light regulatory regime and a reputation for illiquidity.

Undergoing something of a comeback at present, OFEX plays host to Havant-based Clyde Marine Plc, the relatively unknown parent of a very well known offspring, Lewmar Ltd, plus its US sister-company Navtec Inc.

The origins of Clyde Marine lie in the Scottish ship building industry 150 years ago, but over time the company has moved into higher tech businesses and now turns over around £50 million annually via Lewmar and Navtec.

With over 90% of its sales going overseas the company offers a more global exposure than others, and, like all exporters, can both gain and suffer as the US dollar and euro move against sterling.

Despite a highly loyal shareholder base the shares have slid slowly but persistently to their current price of 115p.

Chief executive Arthur MacMillan believes that this offers a buying opportunity for those investors that know the sector as the company has made great strides in recent years to reduce costs while retaining its position of market leader in a highly competitive environment.

Clyde Marine is also introducing a shareholder incentives scheme whereby investors holding a certain number of shares will be entitled to substantial discounts on Lewmar and Navtec products.

Despite the current investment environment, in which a number of companies in other sectors have recently moved from the stockmarket back to private ownership, all the above companies agree that in the long term their stock exchange listings have played a positive role in their development as long term businesses.

Higher visibility was the advantage most often cited, and while all agreed that a market quote requires a greater degree of disclosure when it comes to financial results and trading outlooks, none seemed to regard this as a particular hardship.

With the stockmarket famously driven by a combination of fear and greed, investors can often find themselves on the receiving end of a bumpy ride for no readily apparent reason, and for those with an eye for the downside, there's no harm in remembering the example of Yeoman Plc.

With a combination of handheld chart plotting devices, Brookes and Gatehouse Ltd and the promise of a big breakthrough into the automotive navigation business, the shares hit a high of around 750p in mid 2000, valuing the company at nearly £200 million. But spiralling R&D costs and the failure to make the required sales took their toll, and after a series of disposals Yeoman finally sold out what was left of the business in March 2004 to Trafficmaster Plc.

At 7.5p per share the company was finally valued at just £2.15 million.

Caveat emptor.

Matt Johnson is a partner in ClearLine Communications, a leading marine PR and investor relations agency based in Lymington - www.clearlinecommunications.co.uk