Yes the reserves have rescue swimmers that serve in reserve helo squadrons. It might be tough to get one of those jobs though. I'm not sure if the reserves offer aircrew school to new recruits. In addition, all swimmers have other rates or vocational training ie engine mechanic or electronics tech. Most are antisubmarine warfare operators (run the high tech ASW equipment finding subs). Jumping into rough seas to rescue someone is just their "hobby". So, if you were to pursue this, see a naval reserve recruiter and tell him you want a rate that can get you to aircrew school and rescue swimmer qualified. The active duty training alone would be several months before you were released to drill with a reserve squadron. And you would have to live pretty close to a reserve squadron or travel there at you own expense. This isn't somethng you do from the Naval Reserve Center in Tucson or Springfield.