IPS powers innovative cruiser

The Maritomo C47. Photo / Supplied.

Maritimo's Bill Barry-Cotter has finally relented and installed pod drives on his new C47.

They say it takes a big man to admit he's made a mistake. Well, in the Australian marine industry, they don't come much bigger than Maritimo owner Bill Barry-Cotter.

Barry-Cotter, generally recognised as one of the most innovative of designers and manufacturers, once had little time for pod-drive systems.

But, in a dramatic about-turn, the doyen of Aussie powerboating has designed and built a new 15m sports boat that runs solely on Volvo Penta's IPS drive system, in a move at least partly driven by strong customer demand.

Unlike other drive systems, which are often interchangeable, pod systems require specialised hull shapes to work. In the case of the new Maritimo C47 Sports Cabriolet, the system needs a bit more than that, too.

After committing to produce a pod-driven sports boat, Barry-Cotter awoke one night to a startling revelation: with the weight of engines and drives under the cockpit (as opposed to further forward where they would be in a conventional boat), there was a possibility that a breach of the hull in the engine room could result in a catastrophic sinking from the stern. Such an event could trap people forward.

He called an immediate halt to construction. He then worked with naval architect Stuart Ballantyne to integrate positive buoyancy tanks on either side of the engine room, eliminating the possibility of such a disaster.

This means, according to the Andrew Nicholson, national sales manager at Volvo Penta in Australia, that the C47 Sports Cabriolet is the world's first IPS boat (in the leisure marine market) to come with both watertight bulkheads and buoyancy compartments.

The boat is also the first in the Oceania region to achieve Volvo Penta "Certified Installation" status. Nicholson says this requires meeting a rigorous set of standards that range from the lamination schedule of the hull (in particular, the rings through which the pods extend) to fuel return lines running to the bottom of the fuel tank.

"It means, among other things, that in the event of an underwater collision the pods will work as intended and, in an extreme event, shear off without damaging the integrity of the hull."

One reason Maritimo's customers like pod-drive boats is for their superb manoeuvrability at low speeds. This is particularly appealing to those new to boating and concerned about their ability to safely dock their million-dollar baby.

Pod systems eliminate that concern to a large extent. They also have other advantages.

Although Volvo Penta has suggested that about 13m is the maximum for a pair of IPS600s, Barry Cotter appears to have successfully pushed the envelope higher.

The C47 Sports Cabriolet has a LOA of 15.43m. Its solid GRP hull and GRP/core superstructure displace 16 tonnes. Yet with a pair of twin inline, 435hp, 6-cylinder, 5.5-litre turbocharged and intercooled IPS600 engines, it tops out at 30.2 knots.

Performance like this often comes at price: super-thirsty fuel consumption. But not with the magic of these drive systems.

At what Maritimo call a "heavy weather" cruising speed of 16.2 knots, the engines, which are pulling 2250rpm, are burning a total of just 62 litres per hour (lph). With a fuel capacity of 1800 litres, this means a range of 470 nautical miles.

Accelerate to a "slow cruise" speed of 19.6 knots at 2900rpm and the engines need 90lph and give a range of 392 nautical miles. Up to a fast cruise of 25 knots the rpm is 3250 with 118lph and a range of 381 nautical miles. Even at full speed, the numbers are not too scary: 30.2 knots at 3550rpm uses 166lph and gives a range of 327 nautical miles.

The new C47 is much more than just an IPS-driven boat. It is also an impressive sports cruiser with two spacious cabins (each with their own en suite) and a number of innovative features (it is a Maritimo, after all).

These single-level sports cruisers are becoming more popular in Australia and, as local companies such as Rayglass and (the now-defunct) Genesis have shown, there is also significant demand here.

The trend on both sides of the Tasman is to make these boats as open plan as possible. While one still has to go "down below" to the cabins and heads, the rest of the boat, from boarding platform to helm station should be as connected as possible.

This is certainly the case on the C47. The sliding saloon doors of previous models have been replaced by bi-fold doors that fold back neatly against the cabin-side extensions in the cockpit.

The C47's transom is also a clever affair. A centrally mounted transom module contains a sink and freezer and, if one wishes, a barbecue as well.

The clever bit is that with the push of a button the module, along with a sizeable hunk of the cockpit floor, raises up to reveal a wee "garage", ideal for storing a small tender.

A couple of other features worth noting are the access to the foredeck and the helm station.

Many boats of this sort have little or nothing in the way of side decks. Their designers obviously prefer to use the space to create a beamier cabin. Barry-Cotter has instead installed reasonably wide, low-bulwark-style walkways, made even safer with full-length grab rails on the cabin side.

Not many people go up the foredeck these days and those who do tend to be looking for a place to sunbathe. It is then appropriate that Maritimo has done such a good job of secreting away both the windlass and the anchor. These are both nearly invisible and certainly a far cry from the days when these two pieces of hardware would totally dominate a foredeck.

The helm station is also a little unusual. Normally installed off to one side with either a couple of chairs or a bench seat, the C47 is none of these. Instead it is almost centrally located and has just a single helm chair.

I'm sure Barry-Cotter had a good reason for doing it this way. I just struggle to see what it is (except it does mean a starboard-side companionway that allows good separation between the two cabins below.) I'm just not sure it's worth it.

In my experience, virtually every male on board (certainly every one who has done any boating) wants to cluster around the station and "keep an eye" on things. So I don't see how this would work on the C47 and it appears to be a blemish on what is otherwise an exceptional vessel.

A full review of the Maritimo C47 Sports Cabriolet appears in the July/August issue of Pacific Motoryacht, on sale now or visit www.pacificmotoryacht.com.

MARITIMO C47 SPORTS CABRIOLET

LOA: 15.43m

Beam: 4.85m

Draft: 1m

Displacement: 16,500kg

Max speed: 30.2 knots

Cruise speed: 25 knots

Construction: Solid GRP with cored topsides

Fuel capacity: 1800 litres

Water capacity: 400 litres

Price: Approx $1.3 million


Contact Marine editor Mike Rose on (09) 483-8284; (021) 735-015
or email: mrpr@xtra.co.nz

- NZ HERALD