Re: [Paddlewise] Bilge pump

Based on some calculations I did a number of years ago, it takes
significantly less energy to empty a boat using the larger pump.  I was
comparing 500, 800, and 1100 gph Rule pumps, and considered both the
"official" specs and my own tests.   

Based on my results, I fitted my open whitewater canoe with a Rule 1100,
using a homemade battery pack with 8 alkaline C cells.  I used this
setup during a week-long trip down the Middle Fork of the Salmon. 
Anyone who has run the Middle Fork in an open canoe can tell you that
you have lots of opportunities to use the pump. :-)  On the first day I
put a small crack in my hull when I went over a ledge and my
fully-loaded stern came down on a wedge-shaped rock.  The boat was
leaking water at a slow rate for the rest of the day, requiring frequent
use of the pump.  Even after fixing the leak, the nearly continuous
whitewater gave me lots of opportunities to use the pump.  On some of
the longer class 3 to 4 rapids, I would simply turn on the pump at the
top of the rapid and let it empty the boat as it filled.  In spite of
the fact that I ran everything (no portages) and avoided all of the
"sneak" routes, one set of batteries lasted the entire week-long trip. 
The pumping rate was noticably slower on the last day, but not enough to
render the pump ineffective (or to cause me to change the batteries). 
With less extreme paddling, I find that one set of batteries lasts an
entire season of whitewater paddling.

"Rule 1100 bilge pump: real-world tested; paddler approved."

Dan 


On Thu, 9 Apr 2009 08:07:06 +1000
"rebyl_kayak" <rebyl_kayak_at_energysustained.com> wrote:

> G'Day,
> 
> I'm impressed by the speed and spectacular jet of water coming from a friends
> 1000 GPH 12Volt Rule pump, compared with the paltry trickle produced by the
> 500 GPH 12Volt version.
> 
> Question
> 
> Would a 500 GPH 12 Volt Rule pump use more, less or the same energy/battery
> capacity to empty a cockpit than a 1000GPH 12Volt Rule pump.
***************************************************************************
PaddleWise Paddling Mailing List - Any opinions or suggestions expressed
here are solely those of the writer(s). You must assume the entire
responsibility for reliance upon them. All postings copyright the author.
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************