Owner’s upgrade: How I turned my Princess V48 convertible into a coupe cabriolet

Princess V48 owner Tommy Montaigne was tired of fitting canvas covers every time the weather turned so he set about designing and fitting his own set of folding glass doors.

Tommy Montaigne likes a project. Having spent his childhood summers exploring the sheltered waters of the Stockholm archipelago in his parents’ sportsboat, it was almost inevitable that one day he’d buy a boat of his own.

The trouble was that as a young married man, funds didn’t stretch to anything fast and shiny so he had to make do with an old wooden cabin cruiser that needed a top-to-bottom restoration just to make it seaworthy. Undaunted, he threw himself into the task and discovered that he had a knack for it.


Tommy helps his grandson take charge of the world’s one and only 2009 Princess V48 GT coupé

With the birth of his daughter came the need for more space and comfort so he sold the wooden boat for more than he paid for it and bought a rather tired GRP Fjord 24. That too needed a full interior refit so he went one stage further and fitted a brand new GRP radar arch as well.

For a while this refurbished 24-footer kept him and his growing family happy until he got fed up with the constant battle to keep the covers clean, “I’d spend the first hour of the day washing seagull poo off the covers before we could actually go out so I swore that our next boat would have doors,” recalls Tommy.

Recommended videos for you

He was planning to upgrade to a Fjord 30 when he chanced across an advert in the paper for a Princess 37 flybridge. “I had never heard about Princess boats,” recalls Tommy. “It was love at first sight. You have to remember that back in 1986 a 37-footer was a big boat for the Swedish archipelago”.

Princess V48: Close to perfect?

His new Princess 37 was almost perfect but Tommy still decided to reupholster the seats and replace the carpets to give it a more modern Scandinavian twist. And so the pattern has continued through a boating career that has already spanned five decades and three more Princesses (a 35, a 388 and a 500), all of which he modified.

Article continues below…

Now aged 70 and having sold his advertising design business, Tommy is focussing his energy on being the best possible grandfather to his two grandchildren by taking them boating at every available opportunity.

His current steed is a 2009 Princess V48, the last of the line of open-backed shaftdrive hardtop sportscruisers that were replaced in 2013 by the IPS powered V48 (now the Princess V50). The reasons he chose to buy one of these older models are many; he prefers the sleeker looks of the old boat as well as the simpler shaftdrive set-up.

He also reckons that the last-of-the-line boats tend to be better sorted (any teething issues have long since resolved) and better value as they are usually loaded with optional extras to help sweeten the deal.


Tommy’s 2009 Princess V48 used to be an open hardtop sportscruiser with canvas covers at the back…

He bought his one secondhand in 2018 from Croatia and paid a very reasonable €245,000 for it. It was immaculate in every way, right down to the satin-finished pale oak interior which his fashion designer wife insisted on. And yet there was still one thing that troubled him.

Like that original Fjord 24 he’d owned all those years ago, it still had covers. Admittedly, they were only needed for the aft end of the cockpit that wasn’t covered by the hard top but with such a short summer season in Sweden and the sudden drop in temperatures at the end of the day, the lack of an enclosed heated deck saloon and the daily battle with zips and poppers cut short his enjoyment of it.

What it really needed, he figured, was a set of glass doors that could enclose the forward part of the cockpit on colder days but fold away on warmer ones to maintain the feeling of an open sportscruiser.


The natural place to fit the doors was between the dinette and sunbed but the hardtop didn’t extend that far

In other words, a set of doors that would give it the same flexibility as the new Princess V48 but without the hassle or expense of trading up to a model that in every other respect he didn’t like as much.

It was a simple enough idea but finding a way to do it was a far harder proposition. There was never a factory fit option for doors on this boat so he’d have to design and engineer everything from scratch.

The obvious location for the new doors was at the aft end of the dinette where the seat backs provided a natural divide from the stern sunpad. The only trouble was that the hardtop didn’t reach that far back so it would have to be extended and new side windows added to fill the gap.


Tommy’s sketch for the windows and door

Then there was the problem of finding a suitable set of doors and windows. Tommy’s original idea was to have a swing door on the port side butting up against a top-hinged window over the dinette that would fold up to the underside of the hardtop. He’d seen this solution on a Jeanneau Leader 46 at a boat show and photographed and measured it to see if it could work on his Princess V48.

However, after giving all the measurements to Opacmare, a key supplier to Princess, it soon became clear that this would be tricky.

Not only would it mean extending the hardtop far enough for the window to fold up underneath it, putting extra strain on it, but the window itself would be so large (over 2m wide) that even with two gas struts helping, it would be excessively heavy to lift. Opacmare advised against it and Tommy reluctantly agreed.


Tommy’s research involved trips to boat shows to see other design solutions like this Jeanneau Leader 46

Never give up

Determined not to be beaten, he went back to the drawing board to find an alternative solution. He’d seen plenty of bi-fold windows and doors on houses and wondered if this idea could be adapted for his boat.

He contacted four different manufacturers from all over the world with the measurements and specifications needed but only found one which he felt would deliver the necessary quality and engineering to cope with the harsh marine environment.

Called Solarlux, they were based in Germany but had a Swedish agent and were happy to manufacture a door and matching set of toughened glass bi-fold windows to his exact requirements in marine-grade aluminium.


Bi-fold window mechanism was the key

The sliding window mechanism would be sturdy enough for the job but it needed to be supported by a stainless steel frame that would retain its shape even when the boat was flexing (all GRP boats flex a bit in heavy seas).

Tommy contacted a metal fabricator, mocked up a frame in wood to check the fit (boats are rarely perfectly symmetrical so the height of the gap differed slightly at each end), then mocked it up again in plain steel to find the vertical so that the door wouldn’t swing open when afloat.

Then and only then did he commit to getting it made up in stainless steel with rubber mountings to allow for a small degree of flex.


A stainless steel frame had to be fitted to support the aluminium windows’ folding mechanism

At the same time a local GRP specialist set to work extending the hardtop by 145cm as per the drawings and computer renderings, which Tommy had spent hours refining and checking with the aid of plywood and paper mock-ups to ensure it looked like part of the original design rather than a hasty aftermarket add-on.

He even managed to source the perfect door handle, which he found at a housing exhibition in Stockholm.

The final step in the process was designing and commissioning the side windows needed to fill the triangular gap between the extended hard top, the original side pillars and the new door frame.


A full-width lifting window would have been too heavy

Once again he and his wife went through countless iterations before deciding on the perfect shape, complete with printed edges to hide the seals and chrome Princess crown logos with the words ‘final edition’ emblazoned beneath them on the two glossy black uprights. As Tommy likes to say, “it costs the same whether you design it well or badly, so you might as well try and get it right.”

The end result is so neatly done and so well integrated that at first glance you’d think it was an original factory-fit option. Tommy reckons the extensive refit cost him around €40,000 in total, almost half of which was spent on the GRP work to extend the hardtop.

The bi-fold windows and doors only accounted for around €3,500, with the steel work, side windows, a new diesel heating system, roof-mounted grab rails, bow thruster, state of the art plotter and a helm retrimmed in Alcantara with a matching storage box on the navigator’s side accounting for the rest.


Even with the door and windows shut the rear visibility stays largely unaffected

“I am thrilled with the result,’ Tommy assures us. “We get twice as much use out of the boat as we used to, especially in the autumn. Last season we spent 27 nights on board because my wife is so much happier and more comfortable on the boat now we can open and close it so easily.

“It works like clockwork – the door clunks shut like a Mercedes and windows slide and fold effortlessly. And no more fiddly covers to contend with at the start and end of the day!”

Princess V48 GT: Twice the fun

He reckons the conversion has added around 200kg to the weight of the boat but it’s not enough to make a noticeable difference to its performance or handling.


Details like the roof-mounted grab rails and repositioned nav lights disguise the new hardtop extension

It will still do almost 40 knots flat out and cruises all day at 28-30 knots. Just as importantly it attracts constant interest from other Princess V48 owners and even brokers. In fact one broker reckons that the conversion has added more to the value of the boat than it cost him to do – a rarity for any refit.

Not that Tommy is entirely satisfied. “”I still have a list of around 25 small jobs I’d like to do,” he confesses. “I am constantly looking for new ways of improving things. Even over winter I have the boat stored in a heated shed so that I can tinker with it whenever I need to get out of the house. My friends and I refer to it as our day care centre!”

Given this constant search for perfection, would he ever consider starting all over again with another bigger boat? “I’ve always liked the look of the Princess V62,” admits Tommy. “But I haven’t yet worked out how I’d improve it.” Something tells us he’ll soon find a way…

First published in the February 2021 issue of Motor Boat & Yachting.

If you enjoyed this…

Be first to all the latest boats, gadgets, cruising ideas, buying advice and readers’ adventures with a subscription to Motor Boat & Yachting. Available in both print and digital formats, our monthly magazine will be sent directly to your home or device at a substantial discount to the usual cover price. See our latest offers and save at least 30% off the cover price.