I'd like to fly to Santa Catalina Island (AVX) from the mainland around Los Angeles. There is a portion of this overwater flight where my Cessna 172 will be beyond gliding distance from land. I know that people usually do this flight with only life jackets, but the water is about 64 degrees F (18 °C) right now and I'm pretty sure that if I needed to make a forced landing in the water I may have hypothermia before rescue arrives.
Is it recommended to take an aviation life raft? They're pretty expensive - they start at US$1000 for a two-man raft. I see that raft rentals are available, but that's kind of a big pain, especially because they are going to be shipped from some other location and there is the possibility of needing to reschedule the flight because of weather.
What are the recommendations of authorities? Is there any alternative equipment that would be as effective in this scenario?