about the submersable radio- with you sailing on a lake radio traffic would be less. still i believe if there is a public landing there on lake jordan, wildlife officers or the city park people monitor channels. check where you launch from and what channel they are on. channel 16 is the usual calling channel. tell these people your sailing plan and when you schedule yourself to return. i went thru three radios before i found one that didnt leak and corrode. the raytheon radio in my opinion performs the best and goes for around $200. take along a cell phone in a very water proof container for a back up also.
you should just assume that you will capsize. dont go out without a method to right the boat. practice the method near shore. when you capsize you need to be able to right her without calling for help. what i do is strap a 2x6x5' under the tramp with about 25' of 1/2" rope. when i am over i untie it at the forward cross bar. dont tie it up at the aft cross bar, the boat will pitch aft into the cold cold water when you go to untie it! on my boat (h17) there is a perfect place to plant the base of the 2x6 at the fore cross bar, you may have to tie the base of the 2x6 to the fore cross bar or pylon or what ever there is. throw the rope over the upper hull to support the other end. this gives me enough leverage to right her as i ease out to the end of the 2x6. there is a product on the market that goes for 1 or 2 hundred $. easy righter or something. a 2x6 at lowe's goes for 5.50