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Sea Ranger 448

Report date: April 1999

The Searanger 448 and the Corvette 32 are the unchallenged Odd Couple of the semi-displacement world. Their hull shape is the thing that stands out most – like a giant sausage and an ironing board caught in flagrante.

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Contents

Hull shape and seakeeping
Pros & cons
Comparisons & conclusions
Sea Ranger 448 data
Nelson 38 & 42, Seaward 25, Landguard Nelson 113
Aqua-Star 45

This test was written by David Marsh, a marine architect and published in the April 1999 edition of Motor Boat & Yachting. It is independently hosted by ybw.com, the home of mby.com and offered exclusively to view in this full version by www.searanger.com



pic 1Jack Lemmon and Walter Matthau have nothing on the Corvette 320 and the Sea Ranger 448: the unchallenged Odd Couple of the semi-displacement world. Their hull shape is the thing that stands out most – like a giant sausage and an ironing board caught in flagrante.

We tested the Sea Ranger 448 over a year ago (MBY February 1998), and it turned out to be a great boat. And compared with the Corvette, it has the advantage of 25 years of powerboat development, a world-class designer, and a tank-tested hull. Can the Corvette, and its eccentric 32ft hull designed in 1974, still compete?

pic 1I guessed it wouldn’t work, this strange hull shape. After all, the 45° deadrise at the bow is planing boat territory, hardly the super-fine entry of a Fleming, so along with its huge chine flats, it was bound to slam. And with its immense beam having to shoulder aside so much water, it was destined to be very wet. How annoying when you are so, so wrong.

 


Hull shape and seakeeping

pic 1If you asked a child to combine a Ferrari with a Range Rover, you would probably end up with a very tall, bright red car, which fell over as it went dashing round corners. Something that didn’t work, that is. But by marrying the performance of a planing boat with the low-speed qualities of a semi-displacement hull, this is, of course, exactly what Compton & McGill did in 1974 with the Corvette. And if imitation is the sincerest form of flattery, when the Bill-Dixon-designed Sea Ranger came out in 1997 Corvette must have been very flattered indeed! They both produced a trawler with an odd hull. But why produce such a strange hull shape at all?

There were three things that the designers were trying to achieve: an excellent sea boat with the low-speed benefits of the semi-displacement types with keels; to allow speeds higher than those possible with conventional semi-displacement shapes; and greater efficiency above typical semi-displacement speeds.

A gallon of diesel contains the same amount of energy, whichever boat it is in. So the mpg figure (miles travelled per gallon of fuel) provides an excellent indicator of the efficiency of a hull. The Sea Ranger 448 and the Aqua-Star 45 at 16 knots have identical consumption at 0.91mpg. Above this speed, the Sea Ranger’s efficiency climbs steadily, reaching a maximum 7.5% improvement over the Aqua-Star – a worthwhile saving on fuel.

pic 1A different perspective emerges if we compare the Sea Ranger with the Apreamare Emerald 40 (MBY August 1998). The Apreamare’s shape represents the other route that naval architects explore when trying to combine semi-displacement and planing qualities – very fine vee-sections forward linked to very flat sections aft.

Although the Apreamare is shorter, it weighs the same and has identical 430hp Volvo engines. At a realistic cruising speed of 24 knots, the Sea Ranger achieves 0.68mpg, the Apreamare 1.01mpg – a 48% efficiency increase. However, the comparison needs qualifying. Naval architects know that hull efficiency increases as the centre of gravity moves aft – around +4% for every 1% shift aft. Apreamare are able to position their heavy engines right aft on V-drives, but the aft-cabin trawler configuration of the Sea Ranger rules this out completely. Comparable planing boats are still more efficient than either the Corvette or the Sea Ranger – between 15% and 35%.

pic 1Both are significantly faster than the other trawler types like the Grand Banks, whereas the speedier Nelsons are only a knot or two behind. However, the Corvette and the Sea Ranger are heavier and more voluminous boats than comparable Nelsons, so their hulls have obviously gained ground here.
But take these boats out in a howling gale, and you’re unlikely to be thinking about mpg. More likely it’s the lack of slamming and the dry ride that will impress you. These are the qualities which make these boats so special and so impressive, not their efficiency gains.

Pros & cons

pic 1The Good: huge beam = huge interior volume. Safety around the deck. Excellent engineroom. Abundant storage. Expansive decks, particularly side decks on the Corvette.

The Bad and the Ugly (320): poor flybridge helm ergonomics. Peculiar detailing in places. (448): bow obstructs visibility from the Sea Ranger’s lower helm.

Helms seem to be a blind spot for all the trawlers. The Corvette’s flybridge wheel is too low and the throttles too far forward. Daftest idea of all is obscuring the trim tab controls under the perspex instrument screen. And Grand Banks stubbornly refuse to move the pillar on the GB42 that sprouts very obtrusively from the lower dash, directly in front of the wheel. Curvy, sexy helms are obviously inappropriate,
but all these builders, including Fleming, would benefit from a trip on board a Fairline Squadron 62 and a lesson in human ergonomics.

Overall though, the things that are wrong are little, fiddly, correctable things, and the those that are right are jolly big things. And given Corvette’s proclamation that "the interior of the Corvette is individually hand built... and can be tailor-made to your requirements," it should be easy to wind up with near perfection. The same tailor-made thinking applies to the Sea Ranger – if you want something changed, just ask. Given how little was lacking when we tested the prototype (MBY February 1998), I’d be surprised if customers today cannot buy a relatively fault-free 448.

Comparisons & conclusions

pic 1Nelsons and Aqua-Stars have two very appealing qualities: outstanding seakeeping and the ability to achieve near planing-boat speeds. They also have two unappealing qualities: they’re very wet and they roll a lot. Among Grand Banks’ and Fleming’s many charms are their voluminous interiors and excellent, safe decks. Of course, it would be too much to expect any single boat to have it all: impressive seakeeping, the capacity to reach near planing-boat speeds, be dry, roll very little, provide vast interiors and excellent, safe decks.

But this is exactly what the Corvette and the Sea Ranger are offering. Their hull shapes have bypassed the natural shortcomings of the semi-displacement type, and really do offer the best of all worlds. Sure, the Corvette has a few details in the saloon which need sorting, but it’s really no surprise that Corvettes and Grand Banks are marketed by the same people – when it comes to important things like the engineering and construction, the Corvette is obviously an aspiring baby Grand Banks.

For me, the biggest surprise is not how well the strange hulls perform. It’s that Corvette and Sea Ranger don’t have a two-year waiting list for their boats.
MBY

Sea Ranger 448 data

Length 47ft 11in (14.61m) Beam 15ft 11in (4.84m) Displacement 14.5 tonnes light Engines in test boat Twin 430hp Volvo TAMD73P Fuel capacity 500 imp gal (2,275 litres) Top speed & range 26.0 knots, 258 miles at 2,700rpm


Nelson 38 & 42, Seaward 25, Landguard Nelson 113

pic 1When Commander Peter Thornycroft designed the first Nelson, a 29ft (8.4m) fast commuter for Leopold de Rothschild, in 1959 he started a line of boats that has virtually become generic. For many, a semi-displacement gentlemen’s motor launch can only be a Nelson. It is the definitive type, unchallenged by pretenders to the throne.

Very little has changed in the past 40 years. The persistent demand for more voluminous interiors has occasionally been met with small increases in beam. But few would be able to spot the difference between a hull drawn by Peter Thornycroft in 1959, and one designed in 1999 by Arthur Mursell of TT Boat Designs.
The type’s inherent conservatism has only recently started to be chipped away, with new arrivals like the Dale Nelson 38. Now Nelson buyers can have sexy fittings and fixtures, unusual interiors, and even eccentric exteriors! We rounded up a collection of the conventional and the not so conventional, and put them under the MBY microscope.

pic 1With their 30-knot potential proved by Horatia back in the late 1960s, you might expect the Nelson hulls to bear the closest resemblance to a 30-knot deep-vee planing boat. At first sight though, their round-bilge displacement shape seems as far removed from a Fairline as possible – certainly more so than all the other forms such as the hard-chine Grand Banks, or the Aqua-Star with its small chine. So, given enough power, why does a Nelson have the ability to travel much quicker than a Fleming or a Grand Banks?

Dig a little deeper into Arthur Mursell’s lines plan for the Nelson 42 and you discover the two answers. Near the bow, the sections are actually a deep-vee, with a 45° deadrise indistinguishable to that found on most 30-knot planing boats. So although they appear very different because of the Nelson’s more upright stem and lack of chines and spray rails, there are similarities which allow the Nelson bow to develop dynamic lift: certainly more than the Grand Banks boats. And where the buttock lines on the Grand Banks are still rising towards the stern, the hollow ones on the Nelson flatten off markedly, allowing it to push its stern wave further aft, and develop more dynamic lift along the rest of the hull too. All this means less drag and hence more speed, although even the Nelsons are still ultimately trapped by their wave systems.

pic 1It’s perhaps unfair to lump these four boats together – the Seaward 25, Landguard 113, Dale 38 and the 42 – when describing the handling and performance, but some generalisations can be made. I haven’t tested the 38 (which appears a lot dryer) but driving upwind on the other three, the only time I have been wetter is surf-canoeing in Cornwall. They have no chines to deflect the spray, so even in moderate conditions, solid lumps of water find their way aboard. And although the trawler types are much the same upwind, their flybridge helms are further forward and higher, so you can stay outside without an aqualung for far longer. The Sea Ranger and the Corvette are in a different league, barely getting damp.

In a beam sea, because they have no chines developing dynamic lift, Nelsons sit very level at any speed, which adds much to passenger comfort. Downwind handling is excellent too. When we tested the Seaward 25 for instance, skidding down the steep, 6ft quartering seas around Poole Bay, no amount of deliberate provocation could make the boat misbehave or dig its bows in and broach. The Nelsons are clearly better than the slower trawler yachts here, and there is a strong sense of being on a boat that will take care of you, whatever the conditions.

The Good: legendary rough weather handling.
The Bad and the Ugly: very wet in rough weather. Narrow beam means low-volume interiors. Trawler types much safer on deck.

pic 1Most of the Nelson builders are long-established names: Bucklers Hard, Seaward Marine, Dale Sailing, and Landguard Marine for instance. Bridgend Boat Company are Nelson newcomers, though I’ve been a fan of their high-quality traditional wooden sailing boats for years. There has been a breath of fresh in the Nelson world recently: the interior of Bridgend’s Nelson 42 sports blue Alcantara and light woodwork. Dale are also producing innovative interiors, although they are happy building the conventional too. The novelty is not restricted to below decks either. Seaward have their Menorca 25 (MBY October 1997), an open-deck Nelson, custom built to take advantage of the sun around the owner’s home in Menorca. Having worked with Bucklers Hard in the past – their Aqua-Star 42 has my interior design and styling – I can vouch that they have an imaginative and skilful team, and owners will find them a joy to work with. I would put them at the top of the pile for quality, although the latest from other yards give them serious competition.
Comparisons & conclusions

The things closest to the hearts of buyers of semi-displacement boats are safety, practical interiors, sound engineering, and excellent handling. So how do the Nelsons compare? Well it’s far safer moving around the decks of the trawler types with their waist-high bulwarks. There is a strong practical element running through the interiors of all the boats reviewed in our semi-displacement special, and with the customisation now on offer, most things are possible. But if it’s a truly avant-garde interior you crave, the real custom Nelson builders know no bounds, whereas many of the other manufacturers have some constraints. What money cannot buy is more interior space on the relatively narrow Nelsons, so a Sea Ranger 448, an Aqua-Star 45 or a Tarquin Trader feel far roomier than a Nelson 42. Engineering? It’s the Grand Banks that everybody else has to aspire to here. Enough money could probably guarantee the same quality, but no amount of the folding stuff will secure their stadium-sized enginerooms.

pic 1Which leaves handling. There seems little dispute that in extreme conditions the Nelsons are outstanding. But it’s not a wholly one-sided contest. In everyday cruising, other boats are drier and most roll less. And although the test conditions for the Corvette and the Aqua-Star weren’t extreme their handling suggests they would tackle worse.

So it would seem that Nelsons have a fight on their hands. Or do they? If I could buy one motorbike, it would be a Harley Davidson. It’s expensive, designed in the 1960s, and woefully underpowered – an anachronism of the first order. But that doesn’t matter to me: it’s an icon and I want one. And so it is with a Nelson.

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Aqua-Star 45

pic 1Aqua-Stars are obvious competitors to Nelsons. They have an outwardly similar hull form, and they share the spoils when port authorities come to choose their pilotboats. However, even if you miss the small but significant differences in their hull shapes, moving between a Nelson 42 and Aqua-Star’s new Ocean Star 45 (left) is quite an eye-opener. Surprisingly, there is only 1% difference in overall length between the two, but with 15ft 0in (4.57m) of beam compared with the 12ft 10in (3.92m) of the Nelson 42, strolling onto the Aqua-Star is like moving from a two-up, two-down into a four-bedroom semi.

But as we all know (and hope!), size isn’t everything. The palatial accommodation provided by the Aqua-Star is only one of many things that make or break a boat’s success. In December, we flew to Guernsey to discover the truth about all those other things.

I have talked to numerous buyers trying to choose between semi-displacement and contemporary, high-speed planing powerboats. Two things seem to influence their decisions more than others. Firstly, the look – although many are open minded about the pros and cons of the two types, some are simply more at ease owning a traditional-looking boat. The perceived heavy-weather handling and performance gains also figure highly. But I feel that the biggest differences are often found in the way that builders of semi-displacement boats approach their task.

On deck
pic 1Nowhere are the differences between boatbuilders more obvious than around the decks on the Aqua-Star 45. For instance, the handrails on the flybridge – where you experience the most movement – are higher than on deck. On contemporary powerboats, crew safety is often sacrificed for style, and the handrails lowered for a sleeker look – 10in is the record so far!

And why is it that the semi-displacement crowd take mooring more seriously than those building planing powerboats? The 45’s mooring gear would look quite at home on a modern 60ft powerboat, except for the stainless plates that protect the lovely teak-capped bulwark from abrasion. With a second pair of forward fairleads and secondary spring cleats augmenting all the usual gear, it’s difficult to see how the mooring gear could be improved.

With its full 3ft (0.9m) depth, the 45’s flybridge is firmly in the ‘sit down in’ category, not the ‘perch on top’ class. There’s seating for four adults around the drinks table, with space for two more at the helm. Here, the fixed seat makes it a stretch to reach the wheel and the throttles – an adjustable wheel would help, but a sliding seat would be far better. Our boat sported a barbecue up top, covered with a high-quality (ergo expensive) double-skinned hatch. Many builders still fit flimsier single-skinned alternatives.

Handling & performance
pic 1The 45 performs well compared with its competitors. Pushed along by Volvo’s 370hp TAMD63P engines, and with around 1.5 tonnes of fuel, water and people adding to its bare 15.5 tonnes, the 45 achieved 23.2 knots. That’s on a par with the lighter Nelson 42, and extrapolating from our Sea Ranger 448 test results, only a knot less than the 448 would manage if fitted with the same engines.

Looking at the speed:power curve, there’s no evidence to suggest that the 45’s hull is reaching its limit at 23 knots. So the next obvious jump – the 430/435hp engines – should push the 45 at around 25 knots. And a pair of Volvo’s torquey new 480hp TAMD74’s are only 400kg heavier than the TAMD63P’s, so 26 knots may be possible with these engines.

There’s a simple trade-off between cruising speed and cost, as the fuel consumption improves in line with decreasing speed. Flat out, the sound levels were average, but in the mid-teens, they dropped off noticeably – 16 knots was a very peaceful cruising speed.

Accommodation

pic 1With a total of 27 drawers, lockers and wardrobes to choose from in the aft cabin, fiddles on all the worktops, and a generous 5ft2 (0.5m2)chart table, it’s easy to spot the philosophical differences below too. The saloon has only one noticeable shortcoming, the overly upright seat backs. These are OK for dining, but for comfortable lounging they need more padding just below the lumbar region. Otherwise, the 11ft-wide (3.3m) saloon works well, and will swallow about ten adults before it begins to feel crowded.
Although the galley is down three steep steps, the cook can remain involved in the social activity as this area is open to the saloon. It’s also very spacious. Unfortunately, the door of the eye-level fridge sweeps low across the worktop, rendering this section largely unusable. Swapping it with one of the abundant, large lockers below would restore the otherwise generous worktop, and allow the 45’s galley to make it into my top five, irrespective of boat size.

Aqua-Star have scooped away the bow around the anchor. Along with the deep windows and the elevated steering position, this provides excellent panoramic visibility, good enough to moor the 45 from the inside steering position. There’s enough space here for all sorts of electronic helpers, and the dash is very clearly laid out. The fiddles are particularly useful here as handholds to complement the vertical pillar, and as restraining devices for all the oddments that seem to follow the helmsman around.
With the finish and styling in the cabins receiving so much attention, the heads compartments have been left looking a touch austere in comparison. It all works fine, and it’s good to see handholds here for a change, and the deep shower tray doubling as a hip bath. But a touch more glitz would probably not look out of place.

Engineering & construction

pic 1Were you to peruse Lloyd’s construction rules, you would find there’s a direct trade-off between the requisite hull thickness, and the distance between the frames supporting the skin. Aqua-Star put their trust in heavier laminates, more in keeping with the prodigious lay-ups found on US boats. In comparison, most Nelsons have a monumental lattice of interconnecting frames and stringers, and lighter laminates. Compared with a deep-vee planing hull using duplicate construction, both are far stronger, because their more heavily curved panels are stiffer, and their keels serve as huge additional longitudinal girders.

Entry to the engineroom is possible through the saloon floor, but easier and speedier via the (unnecessarily small) hatch in the owner’s cabin. Once Aqua-Star fit some decent lighting you will be able to see all sorts of impressive things. There are smooth flow-coated engine bearers with drip trays between them to contain spills; orderly wiring, all conduit run; drip-free sternglands; and a luxuriant 3ft between the engines, which helps you avoid the embarrassment of asking your guests’ small children to check the oil, they being the only ones compact enough to work effectively inside the enginerooms of many aft-cabin boats this size.Looked at from afar, it is easy to mistake an Aqua-Star for a Nelson, or vice-versa. And it’s true that of all the myriad shapes tested here, these two bear the strongest resemblance, above and below the waterline. They share the same basic shape, a round bilge form, with the flattish buttock lines that allow them to attain higher speeds than the Grand Banks and the Fleming. But there is a fundamental difference between the two rivals – the Aqua-Star has a narrow, full-length chine. This is barely visible, as it’s low at the bow and enters the water well forward.

pic 1How this affected the handling compared with the Nelson seemed to depend how fast we were travelling. Driving upwind in a Force 5 into the steep, 6ft seas around St Peter Port in Guernsey, at low speeds there was no perceptible difference. If the Aqua-Star’s chines were deflecting a little more spray it was largely academic, as the boat was constantly peppered with solid lumps of water anyway. As soon as the swells lengthened a little, the 45 could be driven upwind much quicker. Rather like the Nelson, it was only in the really steep seas that the hull can be made to slam, and only then if it’s deliberately provoked. Above about 12 knots, the chines do begin to work more, but compared with say the Corvette or the Sea Ranger, the Aqua-Star is still an almighty wet boat, with its rolling still in evidence.

But turn downwind and everything changes. Here, and in big quartering seas, the 45 is a real joy to drive. As the boat gains speed, the chines begin to bite, the rolling disappears, and almost no water finds its way on board. It was impossible to get the boat to misbehave in any way. Even depressing the trim tabs fully, or driving at the ‘wrong’ speed could not unsettle the boat’s balance or provoke it into burying its bow or upset its steering. And like most semi-displacement boats, the 45 has the best of both worlds – excellent directional stability and a very speedy and precise response to the wheel.

The Good: excellent value for money. Practical, spacious interior, especially the saloon and galley. Mooring gear. Abundant storage below. Safety around the deck
The Bad and the Ugly: saloon seat backs too upright. Inadequate engineroom lighting.

pic 1As the owner lives on Guernsey and keeps his boat there full time, Aqua-Star have been able to legitimately omit the VAT from his bills. However, if the boat moves outside Channel Island waters permanently, the VAT becomes due. If you are happy keeping your boat in the Channel Islands, this VAT anomaly does provide a substantial saving on what are already very keenly priced powerboats.

Italy is probably not the first place you would expect to find the joinery for a traditional boat built in Guernsey, but like many boatbuilders, Aqua-Star do not build all their own furniture. In this case, it’s the laminated door frames, complete with beautiful finger joints, used by better builders to ensure a long life. Mimicking the high-gloss finish found aboard contemporary flybridge cruisers is still a novelty among semi-displacement builders. With the large amount of joinery inside these boats, it might have been expected to overpower the interior, but there’s so much space on the 45 that it works very well. The difference between this boat and a Princess for instance, is that Aqua-Star are still using teak, not the ubiquitous American cherry. And teak is, according to Lloyd’s Register, the best wood money can buy, achieving 15 out of 15 straight As in their timber selection guide.

It’s rare to find a boat of any size which has such an effective saloon layout. Almost all the boats I test have dinette tables which are far too small for all the boat’s occupants to dine together in any degree of comfort. And even when they are large enough, they often founder by forcing the diners to crowd around three sides of the table. In its unfolded state, Aqua-Star’s table is large enough for six proper place settings, and the two seats across the saloon can slide across for dining in comfort. Full marks here.

Comparisons & conclusions
pic 1It has been suggested to me on several occasions that an Aqua-Star is a poor man’s Nelson. If that implies unbeatable value for money, the sentiment rings true. But as a pejorative statement it’s very wrong. I confess that we did not test the two Aqua-Stars or the three Nelsons in survival conditions – the sort where experience is at least as important as the boat you pilot. But nothing I found suggested that any of these boats would be anything other than outstanding in these conditions. Of course, neither boat will keep their helmsmen as dry as the Sea Ranger or the Corvette, or roll them around as little.

There was a time when the standard of finish and attention to detail found on the custom-built Nelsons put Aqua-Star in the shade. But over the past three years, Aqua-Star have improved. Any variations in quality are much smaller, certainly no greater than the differences existing between the various Nelson builders. Only Fleming’s and Grand Banks’ engineroom installations are still ahead, but then they are ahead of everybody. Once you start delving into the price list, the Aqua-Star 45 begins to look unbeatable. Even if you assume that some of the Nelsons have a quality edge, they can’t begin to compete with the 45’s interior space. A Grand Banks 46 keep up in the space race, but having to hand over almost £100,000 extra might make you swallow hard. Closest of all for space and quality is the Sea Ranger, which doesn’t roll and keeps you dryer. But there’s the matter of the price difference, amounting to the cost of a Ferrari 355. Mmmm. Decisions, decisions.

In an age when modern planing powerboats are so good, are there really any sound reasons left for buying a semi-displacement boat, other than credibility in the yacht club bar? Of course there are. High-gloss American cherry joinery may be sneaking its way aboard the occasional Aqua-Star, but the differences between the two types are quite profound. And they are becoming more marked as time goes by.

Handling aside, it’s down to safety and practicality, and consequently the way the boats can be used. The trawler types in particular, like the Grand Banks and the Fleming, are inherently far safer boats to be aboard. The deep bulwarks, abundant handrails, and wide teak-laid side decks don’t just keep you aboard in rough weather. You and your kids will also feel the benefits as you wander around the boat when you’re moored in that glitzy marina in Monaco.

pic 1This emphasis on safety tends to pervade the rest of the boat. There’s no reason why the mooring and anchoring gear on semi-displacement boats should be bigger and better than those on planing powerboats – they just are. Of course, there’s some rationale for the differences inside. Contemporary stylists of sleek flybridge boats don’t consider it cool to have their interiors contaminated by things like handrails or pillars to stop the crew lurching across their expansive saloons in rough weather. Nor do they like fiddles around the countertops, which spoil the smooth edges that allow everything to slide gracefully onto the floor as soon as the boat moves. And if you fancy a full-size chart table, rather than a full-size electronic chart plotter, guess where you will find one?

Fairline in particular are making great progress with their helm layouts and ergonomics. But although the helms on their new Squadrons are nearly perfect, the visibility from inside a Fleming or a Grand Banks, for instance, is in a different league entirely. It’s like jumping from a Mercedes coupé into a Range Rover. So however good your anti-collision radar is, in rough conditions, there’s nothing more comforting than being able to see everything as clearly as possible.

It’s just as well that the visibility is so good though, as many semi-displacement boats are more likely to be submerged in an avalanche of spray, especially driving upwind. Ironically, this is where they present the biggest gains. However good contemporary planing powerboat forms are, there’s no substitute for deep, fine bow sections, which remain immersed when you are driving into steep, lumpy seas. In a beam sea it’s a close-run contest. Because they develop less dynamic lift, the semi-displacement forms often sit more level with the horizon. Still, trim tabs can always be used to level a planing powerboat to make it more comfortable. Downwind, modern planing hulls are the top dogs. Big quartering seas are the traditional weak spot of the slower semi-displacement types, and here the extra speed and forward buoyancy of the planing powerboat make them easier to control.

I find the rolling of semi-displacement boats to be a major drawback, although it clearly doesn’t bother everybody. Unless you have the luxury of stabilisers, in most conditions, they roll a lot more than their planing counterparts. Even the most resilient seafarer would not describe them as comfortable.

Conclusion
pic 1All the owners I have met claim that one of the major attractions of a semi-displacement boat is the handling and seakeeping. Interesting then that, when it comes to a contest, it’s clearly not a one-sided battle, with both semi-displacement and planing powerboats able to claim victories in different areas. Rising above this contest though, are the Corvette and the Sea Ranger, the only boats I have driven which combine the best of both worlds.

And what of the giant engines that are finding their way into semi-displacement boats, and the huge cost premium that owners pay to squeeze that final knot from their boats? Better to have the capacity for velocity than not, runs the argument, and who can disagree? And unlike big-engined cars, if the horses aren’t driven hard, they graze very lightly, so Mr 600 horses won’t burn any more fuel than Mr 450 horses when they drive at the same speed.

But it’s the philosophy of the semi-displacement boatbuilders that really makes their boats so different. The ‘style police’ are to blame of course. These increasingly powerful figures prowl the design studios, rounding up fiddles and handrails, oversized cleats and windlasses, and full-size chart tables – anything that spoils ‘the look’. But their jurisdiction simply doesn’t extend to the likes of Grand Banks and Fleming, or Nelson and Aqua-Star. And until it does, there will be people queuing to buy semi-displacement boats.

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