Circa have sent us some initial fuel burn, speed, and engine loading data for the second FPB 64. This information was collected with the boat at about 80% payload, in light winds, and shallow water of the river that runs into Whangerie.
You can tell by the max RPM, 2395, that the hull is feeling the river bottom (we need about 30 feet/9m minimum to be free of the bottom). We would expect 2415/2430 in deep water with all accessories turned off. However, the data is in the ballpark and confirms what we saw with the first FPB 64.
Posted by Steve Dashew (August 8, 2010)
August 8th, 2010 at 11:30 pm
Is there a short description for the “…to be free of the bottom”? Does the bow’s pressure wave interact with the riverbed negatively? Or is more like flying in “ground effect”?
[Reply]
Steve Dashew Reply:
August 9th, 2010 at 6:46 am
Hi Michael:
The pressure wave off the hull will feel the bottom up to water depths of 30 feet/9 meters, even though the actual boundary layer is around eight inches/200mm.
[Reply]