Last year, intent on increasing their market share, Yanmar teamed its 6-cylinder 250 and 300hp diesel engines with Mercruiser sterndrives.
With shaft drive or sterndrive options, Yanmar have been able to supply new boat manufacturers and owners contemplating an engine refit, with engines that have been not just competitively priced, but have comparable horsepower in a much smaller and lighter package.
As a result, Yanmar have quietly achieved sales that have placed them as one of the market leaders in diesel marine propulsion in Australia.
Certain to help their market share and definitely an engine that will interest those owners looking at repowering, is the 3.45-litre 230hp 4-cylinder engine released around the boat shows this year. This engine, due to its compactness and relative light weight for a 230hp diesel, makes it a very viable power option for small to mid-sized cruisers. The compact size of this diesel package will enable manufacturers to lower floor levels, flush up floors, and reduce or possibly even eliminate engine boxes. The 4-cylinder range is to be extended early next year to include 150 and 190hp sterndrive packages and these will undoubtedly further enhance the viability of powering or refitting small cruisers with diesel sterndrive engines.
But, back to the 300hp 6-cylinder sterndrive engine released last year. Yanmar got together a new 10-metre Kevlacat (fitted out for charter work for a maximum of 12 passengers and 2 crew) before the new owner took final delivery and headed off to Lord Howe Island with his new treasure. Twin 300hp diesels are well within the manufacturer’s limits for this boat, so the outstanding response to power and acceleration, and the high offshore cruising speeds were quite flattering to the performance of the engines and that of the hull. Yanmar recommend 2800 to 3200 as the best cruise rpm for these engines, and within these limits, the Kevlacat demonstrates exceptional cruise performance.
Even at the lower 2800, boat speed is in excess of 27 knots, while at 3200 it is getting close to 32 knots. Both of these speeds are far more than any charter boat operator would find necessary for offshore operation, even in the best of conditions, yet the Kevlacat handled without the slightest discomfort or without putting a foot out of place. Given unfavourable sea conditions, an easy 25 knots is possible at 2600rpm, while the hull will still hold the plane quite easily down to 2000rpm or thereabouts.
Impressed as I was with the high-speed cruising ability of this boat and the relative ease by which the 6-cylinder Yanmar diesels rolled out the power, the acceleration of the boat was the impressive aspect. From around 2500rpm and upwards, the response to the throttles is brilliant. The boat literally jumps in response to the throttles and certainly belies the myth that diesels – particularly in cats – can be sluggish in acceleration. Under full power, this 10-metre cat is exceptionally lively and very nimble.
It doesn’t wallow nor make hard work of the turns – in fact unlike many cats, it loves to be pulled tight around, particularly at high speed. The hulls hold on, the boat doesn’t buckle or twist and quite surprisingly it doesn’t exhibit the alarmingly outward lean that used to be the trait of many cats in years gone by – and sometimes still today, in fact! Further, with the boat’s ability to be pulled hard in the turns, the sterndrives were equal to the task, not creating any unnecessary cavitation nor loading of the props.
The turning circle of this boat was exceptionally good either at full throttle or down through the range, and I would add that it’s probably the best of any cat. I applaud Yanmar in their ability to achieve the kind of efficient engine operation that leads to almost non-existence of ‘diesel smoke’. Whether the throttles are slammed wide open or eased up from idle, there is an almost complete absence of the usual black (and extremely ugly) diesel smoke.
It was in all, quite an impressive and spectacular combination of cat design, engine and drive-line selection. Commercial boats can tend to be a little dour, but not this one, and I’m sure that anyone not used to offshore powerboating will come away from any charter or tour operated by owner Bill Shead, very happy and satisfied with their day. Bill Shead had this boat built for a purpose and while its speed and comfort in offshore conditions were of prime importance, economy of operation at higher speeds was essential.
Bill operates Trader Nick’s, the premier resort on Lord Howe Island, 300 nautical miles east of the NSW Mid-North Coast town of Coffs Harbour. This resort, which is located right on the water’s edge at Old Settlement Beach at the northern end of the sheltered lagoon on Lord Howe, offers guests the opportunity of a fast tour around the island, regular fishing and diving trips out to the extremely spectacular Balls Pyramid, charter fishing and diving cruises, or a very peaceful and spectacular fully catered sunrise or sunset cruise.
And of course for all this to be viable, Bill needed a boat that was comfortable in a variety of conditions; fast; and most importantly economical. With the charter and cruise boats that presently operate out of the island, being low-speed displacement and semi-displacement cruisers, with the Kevlacat Bill has the ability to reach previously inaccessible locations offshore quickly and in comfort and give up to 12 passengers a longer time at their destination.
My test runs – limited unfortunately to Sydney Harbour and offshore through the Heads, and not the pristine waters around Lord Howe Island and out to Balls Peak – revealed that Bill has probably achieved all three aims in terms of comfort, speed and economical operation. If you ever get over to Lord Howe Island be sure to look up Bill Shead and ‘The Blue Peter’ at Trader Nick’s. The island isn’t all that large so there’ll be no trouble in finding them, and take a fast run out to the Peak or around the island. Bill will undoubtedly tell you everything about the island, the waters, the fishing … and, of course, his boat.
Story by David Toyer.