Take a look at a SPOT Satellite GPS Locator
It will send OK transmissions every 10 minutes when turned on, however you have the option to hit S.O.S and the company (SPOT) will notify Coast Gaurd etc that is near your location
We have one. We use it on our Boat, Snowmobiling and when I have done Atlantic Ocean crossings aboard private sailboats.
The unit is cheap(around $100) and the years service is cheap as well for the basic service but they also have a Marine Assist that works through BoatUS
SPOT http://www.findmespot.com/en/
Take a look at a SEA KEY which is very similar to SPOT however this hardmounts on your boat. It is a bit more for the unit and the yearly fee is $$$ but offers a few other features; since it is hardmount in the boat it can be left active and you can see your boat( very helpful if ever stolen).
We have one of these as well however do not have it activated when we looked into activating it cost around $400/year
SEA KEY http://www.seakeyna.com/
Carry GOOD flares( both handheld and canister/shell type), also some offshore flares that will burn bright, longer and shoot up higher(PARACHUTE type); go beyond Coast Gaurd approved and get SOLAS
-----------------------------------------------------------------------------------------------------------
Also you have my cell and I can be reached whenever a life situation arises; we fish just about every day however if need be I am only about 10 minuets from were our boat is docked
Try not to fish alone however if you do keep an eye on the weather, it changes VERY quick on Lake O and you can be in the middle of a bad situation before you know it out there