Cummins and Secret Harbour 46 from Sydney to Perth on one tank of diesel

With the help of Cummins MerCruiser Diesel’s Zeus drive system, Mike Antalec’s Secret Harbour 46 recently made the 2,375 nautical mile voyage from Sydney to Perth on just one tank of fuel.

“We used close to 3,100 litres of fuel, leaving a couple of hundred litres in the tank at the end of the journey,” says Antalec, founder of Perth-based Australia Yachts which built Secret Harbour 46.

Antalec skippered the 46-foot luxury motor yacht on the journey. The vessel is equipped with the Zeus system which incorporates steerable pod drive units mounted under the hull with twin counter-rotating, aft-facing propellers.

Each drive unit is coupled to Cummins MerCruiser Diesel QSB engine rated at 480 hp.

Antalec, a US Merchant Marine Master of All Oceans (Unrestricted) with over 20 years experience and 400,000 nautical miles at sea, poses the question: “What other recreational boat could take to sea in a Force 8-9 gale and tackle 8 to 10-metre seas in Bass Strait?

“Some people may think I’m a cowboy, but I went into this knowing what I was doing,” he says, pointing to his experience.

The voyage over three oceans through some of the most treacherous waters in the world started in the Pacific Ocean (after leaving Sydney), took the vessel through Bass Strait into the Southern Ocean, across the Great Australian Bight before rounding Cape Naturalist into the Indian Ocean and home to Perth.

“It took over a month but proved the vessel’s seaworthiness, especially when we ventured into the Force 8-9 gale in Bass Strait near Wilsons Promontory,” says Antalec.

“In calm conditions the vessel made 5.8 knots, burning just 6.6 litres of fuel per hour. In rough conditions the boat went slower and burned more fuel.

“There were a few days when we just decided to push through a 3-metre slop making just 4.5 knots. However, these days were balanced out by the days we had following seas, making 6.4 knots at the same rpm.

“The vessel’s average fuel burn was 1.3 litres per nautical mile at 5.2 knots on one engine running at 970 rpm, but we could have slowed down to 800 or 900 rpm and increased our cruising range even further.

“With this voyage we’ve proven the range, the seaworthiness and low cost of operation of the Secret Harbour 46,” says Antalec. “We couldn’t have achieved this extraordinary efficiency without the Zeus drives.

“A big thing for me with Zeus over the competition is that the props face aft as on a conventional drive which is a safety feature. The last thing I would have wanted was to jump over the side into the shark-infested waters of Bass Strait!”

Antalec supports the claim that Zeus is the world’s most advanced drive system for larger pleasure boats. “Before selecting Zeus for the Secret Harbour 46 we did a thorough comparison with the competition. Zeus won hands down,” he says.

Designed by Mark Ellis and built to Marine Survey 2B, the Secret Harbour 46 is designed to run all day at 28 knots with a range of 560 nautical miles. It has a fully loaded top speed of 32 knots.