52 degrees is very cold without a wetsuit. Although you might "survive" an hour, survival and being able to function are two different things. Wanna check and see? Go swimming from shore and see how long you can stand it - I bet it won't take long! From my experience, after a couple of minutes with just my legs exposed in this kind of temperature they hurt pretty bad.

Don't ever count on any kind of rescue. That, and dependency on electronics, will eventually put you in trouble.