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yosquire · 05-02-2011, 07:55 PM

I think the GPS is a good idea. To add a layer of complication is the 'ground speed' verses 'indicated speed' issue. Similar to aviation, 100mph indicated is equal to 90mph ground speed with a 10mph head wind.

The river I navigate has a current speed of 2-5mph. So if I avoided the paddle wheel for VSS and went straight to GPS, then I would have more accurate MPG readings (since fuel burn is greater and efficiency is reduced traveling upstream.) This would also allow for some interesting trip MPG --(motor up river, float back down to the boat launch.) Though, while pulling a skier indicated MPG would be slightly more useful since it would remain constant upriver vs down river.

Thanks for the input so far.

05-02-2011, 07:55 PM	#6 (permalink)
yosquire EcoModding Lurker Join Date: May 2011 Location: US Posts: 4 Thanks: 0 Thanked 0 Times in 0 Posts	I think the GPS is a good idea. To add a layer of complication is the 'ground speed' verses 'indicated speed' issue. Similar to aviation, 100mph indicated is equal to 90mph ground speed with a 10mph head wind. The river I navigate has a current speed of 2-5mph. So if I avoided the paddle wheel for VSS and went straight to GPS, then I would have more accurate MPG readings (since fuel burn is greater and efficiency is reduced traveling upstream.) This would also allow for some interesting trip MPG --(motor up river, float back down to the boat launch.) Though, while pulling a skier indicated MPG would be slightly more useful since it would remain constant upriver vs down river. Thanks for the input so far.