Journalists from all over Europe and North America have descended on Alcudia for the official launch of Sealine's C39 Coupe.

Journalists from all over Europe and North America have descended on Alcudia for the official launch of Sealine’s C39 Coupe.

The north Mallorca resort played host to no fewer than three examples of the new sports cruiser, each fitted with a different drive system. A fourth debutante, a three-cabin version of Sealine’s existing 42/5 flybridge model, was also launched.

The C39, which features the same extending cockpit system as its bigger sister, marks a departure for Sealine into hard-top design. Large windows, a fully glazed saloon door and a sliding sunroof go a long way towards providing a wind-in-the-hair experience without actual wind, while a bimini-style cover can be quickly rigged to keep the sun out of the cockpit.

Twin berths amidships and a double cabin in the bows are served by two heads compartments.

But all the talk has been of the three drive systems on offer: a rare opportunity to make valid performance comparisons with outwardly identical boats. Most conventional of the three, and likely to prove the most popular, is the twin Volvo Penta installation of 285hp KAD300s with Duoprop legs, priced at UK pnd 168,500 ex VAT and turning in a top speed in 32C air temperature of 35 knots.

At the opposite end of the price scale, weighing in at a hefty UK pnd 221,000 ex VAT, is the Arneson surface-drive option, packing twin 370hp Cummins and producing a marginally greater top speed of 36.5 knots although this is under anticipated final figures once the propellers are finalised. Most innovative, though, and most intriguing to the gaggle of curious journalists, is the ‘tunnel drive’ boat, fitted with an in-line adaptation of Fabio Buzzi’s Ring Drive surface propulsion system, which Sealine have developed in close partnership with ZF/Trimax and Buzzi himself. Reminiscent of Sonny Levi’s early ‘step drive’ boats, Buzzi’s system places the shaft in a short tunnel which is then panelled over to provide a perfectly fair running surface immediately ahead of the propeller. It has been proven in a variety of Buzzi’s military RIBs, but Sealine’s C39 is its first appearance in a leisure craft.

It displayed viceless handling around the marina, although some trim tab adjustments are needed to get the best out of it at speed. The drive shows real promise, but unfortunately for both Sealine and the engineering maestro, the props fitted were short on diameter and long on pitch, cutting 200rpm off the top of the 370hp Cummins’ rev range and holding the top speed down to 37 knots. Ultimately 40 knots should be possible in the right conditions, or maybe 39 in these temperatures.

A 440hp Yanmar-powered C39 with the tunnel drive is promised for the Southampton Boat Show. That will almost certainly be the one to go for.