Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Re: Compass Idea
By:Paul G. Jacobson
Date: 6/12/2001, 12:09 am
In Response To: Re: Compass Idea (John Monfoe)

: Julie mentioned that I should buy
: a clear waterproof pouch made for GPS's that floats and the GPS can be
: operated for different displays while still in the pouch.

: Now, it looks like I could put the
: GPS on COMPASS SCREEN and hang the bagged GPS in front of me for my
: compass just under the front deck. The downside, they eat batteries.

The poor man's approach is to use two ziplock bags. Put the GPS inside the first, seal it, fold over the seal twice. Place this in the second ziplock bag.

The trapped air in the bags lets this float like a cork. Water would have to navigate through both plastic bags before it hit the GPS which is water resistant all by itself. The gaskets and "o" ring seals on my GPS are good for keeping out humidity and rainfall, but they would fail if the GPS was immersed over a foot or two, as the water pressure would force in some moisture. As long as the thing is floating on the surface its own seals work fine, and th plastic bags are insurance.

You can keep a bunch of spare batteries in those plastic bags, too.

Biggest problem I've had with navigating with my GPS is that they rely on having enough satellites in the sky -- and there are some days (and nights) when my part of the midwest seems to get only token coverage from the satellites. The GPS shows what devices are supposed to be above the horizon, and those theoretically should be sending a signal for my use. But, on a few occasions I've see that there were 8 or 9 satellites, but I've only been getting clear signals from one or two of them. and I need three clear signals.

Today I was driving to Wisconsin with my GPS in the car, and hit areas where the GPS reception was spotty. Looking at the map of my route is a joke. It resembles staggering path of a drunkard. Why? Well with incomplete data the GPS would plot a position for me that was incorrect, then a second later it would plot another position for me that was quite some distance away. and each second it would plot a new position. If the positions were 100 feet apart things would be fine. I'd get a reading showing my speed at about 70 mph and my direction would probably be accurate. But when I could not get good reception I got positions plotted that were thousands of feet apart. And the calculations showed I was doing about 326 mph between them!

To add to this morning's humor: The GPS also calculates elevation. The rolling landscape of Southern Wisconsin is anywhere from 600 to 1000 feet above sea level, and I was spending most of my time around an altitude of 850 feet aboe sea level, give or take the height of a hill. However, that was not what the GPS showed when it was acting up. According to it, at times I was attaining an altitude of 11,000 to 13,220 feet -- and this is in a wingless Chevy!

By the way, keep your GPS on while you drive to your put-in point. My previous use of my GPS had been about 70 miles from home. When I turned on the thing this morning, as I pulled out of the driveway, it took almost half an hour to initialize and I got some really flaky output. Apparently it kept trying to relate the limited reception to the previous (70 miles distant) trip.

Mind you. I love my GPS, but I carry a cheap Swiss Army compass that I got from Target. It looks jsut like the Silva compasses sold at Boy Scout stores, but it was a buck or two cheaper.

Hope this helps.

PGJ

Messages In This Thread

Compass Idea
Mike Scarborough -- 6/10/2001, 12:11 pm
An electronics engineer replies
Pete Croft -- 6/12/2001, 12:35 am
try a ball compass
mike allen ---> -- 6/12/2001, 11:29 am
Re: Compass Idea
daren neufeld -- 6/11/2001, 10:12 pm
keeping an ( old) eye on that Compass Idea
Paul G. Jacobson -- 6/12/2001, 12:22 am
Re: Compass Idea
Doug K -- 6/11/2001, 2:21 pm
&
Doug K -- 6/11/2001, 2:27 pm
Re: &
Doug K -- 6/11/2001, 2:30 pm
whatcha really need is....... :)
Julie Kanarr -- 6/11/2001, 3:40 pm
Re: whatcha really need is....... :)
Scott -- 6/11/2001, 5:19 pm
Re: whatcha really need is....... :)
Julie Kanarr -- 6/11/2001, 5:53 pm
Re: whatcha really need is....... :)
Doug K -- 6/11/2001, 6:43 pm
Re: whatcha really need is....... :)
Ross Sieber -- 6/13/2001, 4:32 pm
Re: whatcha really need is....... :)
Doug K -- 6/14/2001, 10:21 am
I'm not so sure about that idea
Dean Trexel -- 6/11/2001, 2:17 pm
Re: I'm not so sure about that idea
James Neely -- 6/11/2001, 5:57 pm
Re: Compass Idea
John Monfoe -- 6/11/2001, 6:55 am
Re: Compass Idea
Paul G. Jacobson -- 6/12/2001, 12:09 am
Re: Compass Idea
John Monfoe -- 6/12/2001, 8:06 am
Re: Compass Idea
Paul G. Jacobson -- 6/12/2001, 7:01 pm
It works just like you said it would Paul. Thanks *NM*
John Monfoe -- 6/13/2001, 6:40 am
Re: Compass Idea
Shawn Baker -- 6/11/2001, 10:38 am
Link to REI
Julie Kanarr -- 6/11/2001, 9:34 am
Re: Compass Idea
risto -- 6/11/2001, 4:54 am
Re: Compass Idea
erez -- 6/11/2001, 1:15 am
Now that's using you head :) *Pic*
Paul G. Jacobson -- 6/10/2001, 7:08 pm
Re: Compass Idea
Glenn m -- 6/10/2001, 5:17 pm