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Old 09-25-2019, 07:17 PM   #12
rgano
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City: Southport, FL near Panama City
Vessel Name: FROLIC
Vessel Model: Mainship 30 Pilot II since 2015. GB-42 1986-2015. Former Unlimited Tonnage Master
Join Date: Oct 2007
Posts: 4,984
The hull speed of my GB42 was 8.6 knots and for years I ran my twin Lehman 120s with 2.01:1 and 1.91:1 trannies at 1800 RPM getting exactly that speed. Eventually, I found that 1600 RPM was a vert sweet and quieter spot for those particular engines at 8 knots on the nose. Any more power in this hull is just not necessary unless you are planning to waste a lot of fuel to achieve marginal speed increase.
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Rich Gano
FROLIC (2005 MainShip 30 Pilot II)
Panama City area
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