What's your cruising speed.

smitty477 said:

I am not familiar with that Navigator or those specific engines but here is a boat test on a 2004 - 56' Navigator that may help out some....
https://www.powerandmotoryacht.com/boats/navigator-56

I have found at times you can also get additional information that is not online by heading to your local library and asking for help with the microfilm and past periodicals - helped me secure some old boating tests that I then copied.

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Baker said:

So If I did the math right..... .53...almost 2 gallons per mile. Not bad for a boat that size. It is still almost 20,000 pounds lighter than the boat in question.

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smitty477 said:

I do not know this sized Navigator but my math seems to agree at about 0.55 nmpg at WOT.
My best guess (and only a guess) is that with a 0.55 at WOT the nmpg at say 66% of WOT would be much higher. The weights are really unknown between the two since each of them would need to be confirmed.
Navigator had one hull design for a large % of their boats and just 'extended' it for various lengths of their boats.

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