• … even on a wet and gloomy day, with all the light that pours into the saloon, it feels warm and inviting.
  • This coupé is safe, roomy and sociably arranged – inside and out. It’s also nippy, versatile (in the cabin department) and exceptionally easy to handle and manoeuvre.
  • ‘Easy-going’ best describes the handling.
  • The C430 has a large and lazy turning circle, but its angle of lean is very comfortable …
  • … its gifts extend far beyond the gaggle of gargantuan glazing.

Sealine C430
Dave Marsh scrutinises and test-drives the new Sealine C430 and discovers a boat packed with many obvious qualities – plus a few not-so-hidden ‘extras’ …
Isn’t it amazing how much this genre of boat has changed over the years? Sports cruisers used to be wind-in-the-hair machines. Then some bright spark, presumably with a pathological aversion to fiddling around with wobbly stainless scaffolding and acres of uncooperative canvas at the end of an otherwise soothing day’s boating, came up with the idea of adding a hardtop. Next, designers purloined the patio doors that had previously been the preserve of flybridge cruisers. And hey presto: a new genre of hardtop coupés began to emerge that were to all intents and purposes comfy flybridge cruisers – without a flybridge.
Some of us, though, realised that we missed the open-air feel of the flybridge and the tremendous view it gave us. So designers took note and began to concentrate on blurring the distinction between inside and outside. And if any 44ft mainstream coupé could currently claim to represent the apotheosis of this idea, it’s probably Sealine’s new C430. The abnormally deep side windows in the saloon extend all the way down to deck level, so the view out is truly amazing for a cruiser this size. There’s an opening sunroof, but the aft section of the saloon ceiling is also glazed. A window between the galley and the cockpit opens up this area, but there’s more still in the form of a cockpit roof canopy that concertinas away to let the sunshine in. Finally, owners can opt for a sliding door alongside the helm, plus another big electric window on the port side.
But a great view out and the feeling of a strong connection with the watery world outside are far from being the only benefits. Ventilation is improved dramatically, as is the ability to communicate with the crew on deck, especially forward. It’s easier to pass food and drink, among other things, to the right place. And what’s easy to underestimate is the big improvement in on-board safety. The combination of joystick control, bow thruster, starboard side door and twin spring cleats means that confident helmsmen should have no difficulty manoeuvring and tying up alongside in tricky conditions even if they’re single-handed. Likewise, that side door speeds up and improves everybody’s movement around the deck, underway or at rest, especially when it’s combined with the C430’s good side decks and deep toe rails, which become mini-bulwarks in places. Once you have cruised on board a boat with a side door, trust me, you will never want to go back to a boat without one.

Inside Story
The other great change that has affected almost all of our comfy cruisers, coupé or otherwise, is that they have steadily grown in volume. Builders continue to design boats that are comparatively wider and taller relative to their length, and outside of the US, the C430 is probably the reigning king in its class. One result is its unusual full-beam midships owner’s cabin that sports a pair of entrance doors, each leading to a different side of the cabin. So although it’s easy to duck beneath the overhead intrusion at the foot of the large (1.60m/63in wide) double berth, you don’t have to, so the movement in and around the cabin has become easier.
Sealine offer a pair of alternatives to replace this standard midships cabin: one option comprises a brace of double-berth cabins, while the other layout provides a double-berth space plus a twin-berth cabin. Storage is going to be curtailed in these cabins, but in single-cabin form it’s very good indeed. In its three-cabin form, the forward cabin would become the master cabin, and it comes in standard double-berth form or with optional (£2,128) scissor-action singles, which can slide together to form a double. The way the layout works means that (in two-cabin form) the midship master cabin’s en suite heads also serves as the day heads, but it’s a good trade because this arrangement allows the forward heads to be en suite too. In addition, the two heads have the same mirror-image footprint, so in three-cabin form the forward master isn’t short-changed with a smaller heads. All told, the way the accommodation works in its different forms has been extremely well thought out.

On The Water
Tests that take place in completely flat water are not as uninformative as you might think. Of course, it’s risky to predict how a boat might behave in rough weather, even when you have a history of testing numerous generically similar hull forms from the same boatbuilder – which is definitely not the case here. However, the performance figures are normally more accurate. It’s also sometimes easier to decipher the nuances of the handling and the trim when you’re not leaping between spine-jarring wave crests. Our flat-water test did give us a good top speed – 34.7 knots over a two-way run with the C430’s most powerful twin 435hp IPS600 option. In theory, all other things being equal, that should give top speeds of around 32 and 29 knots, respectively, with the two less powerful 370hp IPS500 and 300hp IPS400 options.
That 29 knots may sound OK, but I’d advise against fitting the IPS400. The 300hp engine is Volvo’s D4, and its 4-cylinder form is not as inherently smooth or quiet as the 6-cylinder D6 option. The engine room is vast, so there are no service access issues with the big engines. Moreover, additional extras not fitted to our boat could make for a considerably heavier C430, and the IPS’s dual propellers generally perform better when they’re free revving and lightly loaded. So although Sealine helpfully offer two or three propeller options, I suspect that a heavier C430 than ours with an IPS400 could suffer a disproportionate performance hit.
Despite the flat water, we decided not to conduct full-speed trials. Our prototype boat had a static list to starboard of around 0.5 degrees, and that increased steadily as we accelerated. Prototype boats are normally ballasted once they’re launched, but the dealers – Shepherds Marine on Lake Windermere – have decided to go one better and wait until the owner has everything possible on board, and then level the boat.
I became quite excited when I read about the undisputed Rolls-Royce of interceptor trim systems – Humphree – in one of Sealine’s press releases. However, the system fitted to our boat was called ‘Hydrotab’, and more crucially, it wasn’t working. That point was pertinent because, although our C430 ran along sweetly at speed with about 5 degrees of bow-up trim, at lower speeds, before it settled fully onto the plane, its trim climbed to around 9–10 degrees. And that was without a tender (a 315kg Williams 285, say?) sitting on the bathing platform, or a life raft in its dedicated storage coffer under the cockpit seats, or crew sitting in the cockpit, or the optional 358kg Seakeeper gyro that Sealine have shrewdly allowed for in their engine room.
Sealine talk of the interceptors keeping the bow low, improving visibility, lowering fuel consumption and quickening the transition onto the plane. In fact, even with an inoperable trim system, the forward visibility was absolutely fine. However, given that a differently equipped C430 might trim even more highly, and require frequent input from the helmsman to get the best out of the boat, I feel that Sealine should put their money where their mouth is and fit an automatic trim system (in place of the standard manual system), and not charge their customers an extra £7,048 for the pleasure.
‘Easy-going’ best describes the handling. The C430 has a large and lazy turning circle, but its angle of lean is very comfortable, producing what I call a neutral-G turn – one where you don’t fall in towards the turn, but nor are you forced outboard. Although there’s no height adjustment on the standard helm seat, even a 1.68m (5ft 6in)-tall human can see out fine over the dash and the foredeck. Sealine used to produce the most ingenious, practical, functional dashes I’ve ever come across, but although this one is disappointingly simplistic, it works OK.
Flat water is not the best for testing Sealine’s claim that they have ‘transferred the wave-piercing concept from offshore yachts to a motor boat whereby big waves are cut from the lower part of the stem’. That said, we did have our own modest wake to cross, and the experience was certainly not wave-piercing. Instead, we generally smacked noisily and harshly over the wake. My guess is that the lack of an operable trim system was affecting the ride, so along with fuel consumption data, at this point we’ll have to consider the C430’s ride quality to be unconfirmed.

I reckon that how you judge and value the C430 could depend on the worth you attach to its terrific design. Sealine’s latest coupé kicks off at £452,816 (with IPS600), and at that point it’s a basic boat. Unless you intend to fit your own navigation instruments and entertainment gear, you ain’t going to be avoiding the extras list. On the one hand, that list is very comprehensive, with considerable choice in some areas and interesting options that you might not have expected to see on a 44ft mainstream coupé – the Seakeeper gyro, a wine cooler, two sizes of dashboard and underwater lights, for example. On the other hand, is it really sporting of Sealine to make the indispensable electric windlass and the adjustable steering wheel (an essential element of good helm ergonomics) part of a £12,982 take-it-or-leave-it bundle? The C430’s cockpit table is a terrific piece of design, but be prepared to hand over £3,218 (£5,946 for the high-low version) or you won’t get one at all. I consider the side door to be a crucial part of what makes the C430 such a great boat, but guess what, that’s an extra too. And so on.
However, those niggles evaporated when I scrutinised the C430 over the course of two days, during the final one of our three visits, at its eventual home on Lake Windermere. Here, pottering around at the lake’s 10-knot speed limit did not seem untoward at all, despite the boat’s 35-knot potential. At this gentle pace, the character of the C430 had the chance to shine through most brightly. As our pictures show, even on a wet and gloomy day, with all the light that pours into the saloon, it felt warm and inviting. The sight of the grandiose Storrs Hall hotel in the background only served to emphasise what a great view out this boat provides. But its gifts extend far beyond the gaggle of gargantuan glazing. This coupé is safe, roomy and sociably arranged – inside and out. It’s also nippy, versatile (in the cabin department) and exceptionally easy to handle and manoeuvre. Little wonder our boat’s owner seems content to enjoy the C430’s myriad qualities at a more leisurely pace.


  • Length overall: 13.55m (44ft 5in)
  • Beam: 4.20m (13ft 9in)
  • Fuel capacity: 1100 litres (241 imp. gal.)
  • Water capacity: 450 litres (98 imp. gal.)
  • Draught: 1.00m (3ft 3in) (PBR estimate)
  • Air draught: 3.59m (11ft 9in) exc. mast; 4.86m (15ft 11in) inc. mast
  • RCD category: B (for 12 people)
  • Displacement: 13.4 tonnes

Prices (inc. 20% UK VAT)
Starting prices: £401,544 (twin 300hp IPS400); £452,816 (twin 435hp IPS600)

Notable Extras

  • Automatic interceptor trim system: £7,048
  • Opening saloon side door: £4,309
  • Electric cockpit roof canopy: £4,254
  • Cockpit table + electric engine hatch: £3,218
  • Electric saloon window (port side): £5,346
  • Bow thruster: £5,346
  • High-low bathing platform: £23,891
  • 8kW generator: £17,346
  • European air conditioning: £16,254


  • Smallest engines: Twin 300hp IPS400
  • Biggest engines: Twin 435hp IPS600
  • Test engines: Twin Volvo D6-435 IPS600, 435hp @ 3500rpm, 6-cylinder 5.5-litre diesel

Performance Data
Top speed is 34.7 knots at 3500rpm. Fuel 37gph (0.94mpg) giving a range (with 20% reserve) of 182 miles. Calculated figures based on readings from on-board fuel gauge (your figures may vary considerably), 50% fuel, 50% water, 2 crew + full owner’s stores, but no tender or life raft or Seakeeper gyro, flat water + F1/2 for speed trials.


  • Spectacular panoramic views out from the saloon
  • Exceptionally safe and easy movement around deck
  • Generous berth sizes and good headroom
  • 2- or 3-cabin versions + further mix ’n’ match options
  • Enormous bathing platform (optionally high-low)
  • Terrific foredeck area for socialising
  • A comprehensive range of interesting extras


  • Too many key features are extras
  • Ride quality unconfirmed

Supplying dealer: www.shepherdsmarine.co.uk
UK distributor: www.tbsboats.com

Premier Marinas - Launch at the tap of the App
Cannes Yachting Festival 2024

Arksen Discovery Series


Henri Lloyd

Yamaha - The most exciting way to get from A to B campaign