Yanmar Provides Power & Confidence For Spoilsport


Spoilsport repowered by Yanmar 6HYM-WET engines

Mike Ball Dive Expeditions is known the world over as being a pioneer in the liveaboard dive business. While the business once operated a three vessel-strong fleet into the Coral Sea, today there is just their flagship vessel Spoilsport… recently repowered by Yanmar 6HYM-WET engines and performing exceptionally well.

Spoilsport was built by Austal in WA in 1989, purpose-designed by Mike Ball as a liveaboard dive boat. The vessel is a substantial catamaran, measuring 30m loa with a 10.5m beam and massive displacement of 328 tonnes.

Operating on a strict seven-day cycle, there is zero margin for downtime with Spoilsport. She berths in Cairns on a Thursday morning. Guests disembark, the boat is cleaned, reprovisioned and a new group of divers are welcomed on board ready for cast-off late Thursday afternoon.

The skipper heads straight out into the Coral Sea and steams 100 Nm overnight to the first dive location. Thereafter Spoilsport is on the move every night heading as far north as Lizard Island before heading south back to Cairns for Thursday morning berthing. Every week Spoilsport travels around 440 Nm, logs 44 engine hours and burns 4,400 litres of diesel fuel for both the Yanmar engines and on-board generator sets.

According to Craig Stephen, Operations Manager at Mike Ball Expeditions, this is a tight, professional operation with zero opportunity for anything but routine maintenance.

“We are at sea hosting Mike Ball customers for 48 weeks of every year,” Craig Stephen said.

“Our dive expeditions are at the top end of the market and our customers rightfully expect a premium service. Understandably, the pressure is on and we do not make any allowance for downtime or unscheduled problems. Reliability is everything in this business.”

When Spoilsport was launched she was fitted with a pair of American marinized electronic truck engines which were replaced, ‘like-for-like’ at the first re-power. “The window to re-power was looming, but we couldn’t justify the hefty price ticket to again repower with the original brand of engines,” Craig Stephen said.

“I tend to take notice of what the other charter boat operators and commercial fishermen are doing when they repower their vessels. The Yanmar name is definitely the most common brand being installed. Moreover, there are excellent reports which we hear following the commercial repowers.”

Craig Stephen and the management team looked closely at Yanmar and decided to repower with a pair of Yanmar 6HYM-WET marine diesel engines. In addition to the local testimonials, Craig Stephen liked the fact that the Yanmar 6HYM-WET is a mechanical engine. It is capable of logging big hours and is acknowledged as a commercial workhorse with long service intervals and high reliability.

The Yanmar 6HYM-WET is a purpose-built commercial marine engine. The engine is a 6 cylinder in-line block which has a displacement of 13.733 litres and an all up weight of 1386 kgs.

The 6HY series is available with 4 power outputs ranging from 500mhp (368kW) to 700mhp (515kW). For the repower of Spoilsport the choice was made to use the conservative and heavy-duty continuous rating of 500mhp (368kW) @1950rpm, a decision which will no doubt pay dividends in years to come.

This model includes Yanmar’s latest combustion chamber design, named ASSIGN, a system originally pioneered by Yanmar on their large bore, low-speed propulsion engines. These engines are IMO Tier 2 compliant, ensuring emissions are exceptionally low, an important consideration when operating on the Great Barrier Reef.

The ASSIGN technology combined with Yanmar’s mechanical fuel system provides commercial operators with excellent fuel economy. The cylinder head is a quad valve design. In this configuration, the Yanmar 6HYM-WET excels in conditions demanding continuous commercial use such as Spoilsport and their unforgiving 7 days a week schedule.

Once the Yanmar repower was complete (inside the annual 4-week service break), Spoilsport returned to full service. Skipper Trevor Jackson immediately noticed the improved performance. Importantly, the Yanmar engines provided him with a new level of confidence when at sea.

“There was a noticeable difference right away,” said Trevor Jackson.

“It was the responsiveness to the throttle that I picked up on instantly. Every day, many times a day, we come up on the reef and Spoilsport is so close that the reef disappears under the overhang of the bow. With current, wind and tide this vessel continually moves around. So when I snap on the throttles, I want the engines to gun me back quickly, and that’s exactly what the Yanmar 6HYM-WET engines do.”

Underway the Yanmar 6HYM-WET engines tick over at a comfortable 1400 rpm to deliver 9.5 knots. Although the engines selected are rated to deliver maximum power at 1950 rpm, the design of the hull is such that the extra power doesn’t push Spoilsport any faster.

While the performance, fuel consumption and noise levels are all readily quantified and provide positive feedback, it’s the seat-of-the-pants feeling of safety which has Trevor Jackson most impressed with Yanmar.

“When we are at sea, we’re out there on own, hundreds of miles from anywhere. Rarely do we even see another ship on our seven day expedition. Yanmar gives me an uncanny sense of security; a feeling that with Yanmar we’re in good hands. I never felt that with our previous electronic engines.”

“The crew and I like the mechanical fuel management systems on the Yanmar 6HYM-WET. If there is a problem in the engine room while we’re at sea, the only people who can fix it are those of us on board. And that’s why we like our new Yanmar engines.”

The Yanmar engines are very similar in power, fuel consumption, weight and installation envelope to the previous engines. However, with a significant purchase price advantage and the benefit of peace-of-mind mechanical systems, the Yanmar 6HYM-WET engines have proven themselves to be a wise acquisition to power Spoilsport.