I actually have an Italian gold medal of Jesus with a Mariners' Cross on the back. The inscription around the Cross says "Dio Ti Protegga" is the prayer I usually say when I take it on or off. I received it when I was 8 from the elderly Italian parents of a neighbor - these folks were more like family than friends to me. And since I had no grandparents after 7 years old, they almost adopted me.
I wore the medal for 30 years and the gold started to wear a little too much on the bale and I had to put it away and try to find a jeweler. (It's 18K with a 22K image of Jesus - so it's soft. It's also one of a kind. My neighbor's relative made it in Italy for me. I never could bear to send it out and risk losing it.) I finally found a local jeweler who would fix it while I waited and he restored it - and he told me I shouldn't sleep with it on. He was amazed that the image itself was in such excellent condition. I do have to take it off from time to time - I run with it on - but I also do shotput and javelin and I don't want to risk an accident.
I've always said the prayer printed on the back "Dio Ti Protegga" before putting it on or off. My husband thinks it odd, but I do kiss it when I take it on or off. (He's a religious guy, but is more of a kneeler and bower and less of a kisser.