In preparation for an attempt to break the 270-mile Around-Long-Island record he set with former offshore racer Stuart Hayim of Recovery race team fame three years ago, ace throttleman John Tomlinson logged time on the waters off Miami this week in Hayim’s 50-foot Marine Technology, Inc., catamaran earlier this week. A modified version of MTI‘s 52-footer—it has the same running surface but has a shorter deck—the cat is powered by twin Mercury Racing 1650 engines.
Said Tomlinson on the strategy for record run in Hayim’s 50-footer (shown here at TNT): “Conditions allowing, we’ll probably try to ‘park it’ at 150, 155 mph.”
Hayim has said he would like to complete the two-hour circumnavigation in less than two hours—the record he set with Tomlinson in 2012 is 2 hours and 11 minutes. Managing fuel consumption is critical, which is why Tomlinson, a renowned throttleman who co-owns TNT Custom Marine with Mike Thomas in Miami, has been gathering fuel consumption numbers.
“It varies quite a bit,” he said. “If you’re throttling a lot in the chop, fuel consumption goes up over what it is when you’re able to hold the boat at a constant speed in smoother water. At 150 to 153 mph, we burned (for both engines combined) 195 to 200 gallons per hour. At 160 mph, it was 270 gallons per hour. At wide open, running like 172, 173 mph, it was 317 gallons per hour. Conditions allowing, we’ll probably try to ‘park it’ at 150, 155 mph.
“We’re carrying an extra 300 gallons of fuel, which gives up a total of 570 gallons—I’d say 550 gallons ‘useable,'” he continued. “We should have more than enough. Last year, with the 1350-engine boat I believe we used 430 to 450 gallons.”
Of equal concern to Tomlinson—and something he paid close attention to during this week’s tests—is water-pressure for the 1,650-hp turbocharged engines. Tomlinson said the balance between having low enough pressure at the high end—ideally 45 to 55 psi for Mercury Racing 1650s—while retaining enough pressure for mid-range operation is tricky to find.
“With all the 1650 boats, what happens with the fast ones at wide-open throttle is you can get so much water pressure that you risk blowing off a hose,” he explained. “So you try to adjust the water pressure so that you have good water pressure on top, but then in the mid-range you don’t get enough. We are working on it. We have added some pop-off valves to the systems and are making adjustments.
“At high speed, you can see water pressures of 70 to 80 pounds with 1650s during offshore races,” he continued. “But those pressures are almost never held long off enough to blow off a hose. But in a long endurance run like this one, you could run into some issues if your don’t manage the water pressure.”
Tomlinson will continue testing the 50-footer for couple of weeks. After that, the boat will be sent to Hayim—it’s owner and driver for the run—in New York. Hayim and Tomlinson are planning to attempt the run in August when the weather forecast is ideal.