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Old 02-22-2016, 04:04 PM   #1
dkasprzak
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City: Currently - Aransas Pass
Country: USA
Vessel Name: Hattini
Vessel Model: 1985 43' Hatteras Motor Yacht
Join Date: Oct 2011
Posts: 63
Bottom Job - Props Tuned new performance numbers

I finally had the opportunity to take the boat out after the completion of the bottom job and the props being tuned. Prior to this work it would take 1500 RPMs to get to and maintain 7.0 - 7.5 kts and WOT would produce approximately 17 kts.

This past Saturday went out for a short day cruise, the first leg was 3.8 nautical miles with the wind blowing about 90 to 110 deg off the starboard side. The second leg was 3 nautical miles into the wind, and the final leg was approximately 6.5 nautical miles with the wind off the port quarter.

On the first leg I was able to maintain 7.5 - 8.0 kts at 1300 RPMs. The second leg into the wind the speed dropped only slightly (I suspect a lift from the current) to 7.0 - 7.5 kts at 1300 RPMs. The third leg with the wind quartering from behind I was able to maintain 7.5 - 8.0 kts at 1200 RPMs.

I only tested WOT on the third leg but did see an increase in speed to 18.3 kts with very short up ticks to 18.5 kts.

I am very pleased with these numbers and hope that the reduced RPMs at hull speed will relate into measurable fuel savings. That would be a nice bonus. We are planning a three day trip of approximately 180 nautical miles in May so I hope to average fuel usage over that trip. I will very pleased to see a total of 5 GPH or less.
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