Just to share the difference between my on-camera Rode VideoMic (which is a great mic in most circumstances, and I use it all the time) and the Azden Lapel Mic the groom was wearing connecting to my Olympus LS-10 recorder in his back pocket.
All I could hear while standing on this beach was the waves, the were LOUD. This was the first time I was really nervous about my audio situation, I had the officiant and the groom miked up, but would it be enough? I got back to the room afterwards and immediately checked the audio, quickly (and literally) jumping up for joy when I heard how great it sounded. Thanks Olympus! (No sponsorship deal, I just love them...but I'm here if they want to talk!)