View Single Post
Old 07-25-2012, 05:42 PM   #16
RickB
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Quote:
Originally Posted by Marin View Post
So regardless of what the current and wind are doing to your speed over the bottom, your speed through the water, and therefore your fuel burn, will always be the same at x-rpm.
Ah come on Marin ...

If are cruising along through the water at around half throttle and just under 8 knots your boat will require X horsepower and burn Y fuel. That is kind of a no-brainer and no one can find anything there to argue about ... probably.

But after jotting down your fuel burn as displayed on the hyper accurate Burn-O-Matic Marine Fuel Management Computer that was just installed, the breeze came up, right on the bow at 20 knots. You keep moving through the water at exactly the same speed according to the optional Nav-O-Matic Hull Speed Module you shelled out to have installed along with the Burn-O-Matic, what do you think the fuel flow will show on the Flow-O-Matic module?

If you are driving a typical trawler style boat with about a 12 foot beam and a house about 10 feet high above the waterline, what do you think the horsepower readout will show on the Pow-O-Matic Module?

A. The same

B. 5 HP less

C. 6 HP more

D. The RPM will decrease

The answer is:
A
B
C
D
B and D,
A and D
B and C
RickB is offline   Reply With Quote