I see it as a good anti-theft measure, as long as you don't use iphoone which does not allow the insta-mapper app to run in background (unnoticeable to the thief)
All needed now is a loud, obnoxious noise at a push of a remote button. You track down your stolen phone coordinates, push the button and the miscreant drops the phone and runs like hell...

Now, the kayaking part:
1. Set out in your boat in some direction and keep paddling for a while
2. Make sure you have Google maps up and running on your phone.
3. Start up the insta-mapper and here you are: 60'24'34.10 N 85'40'34.31 W heading WNW at 4 knots
Advanced users will not need the insta-mapper because they already know
60'24'34.10 N 85'40'34.31 W is in the middle of Hudson Bay.
PS. but seriously, I wonder what is the coverage of insta-mapper servers...

: http://www.instamapper.com

: try the demo. it's free, as long as you have the right phone.

: i use it with an iphone, my wife at home can see where i am on the desktop.

: other pay gps spotters are better i suppose. I have found i always use it
: when i launch, the newest version no longer is a big drain on my battery.