For beach weddings I've been using a Think Tank Pro Speedbelt with several bags from the Think Tank Skin Component System.
The Speedbelt is padded, so it's pretty comfortable to wear when running around.
When you attach a modular component bag to the belt, you can choose whether or not to lock it in place by inserting the plastic tab on the back of the component bag into a loop on the belt.
Since I use the Spider Holster rigs to attach my cameras to the belt, I usually prefer not to lock the bags in place, so that I can slide them forward when I need them then slide them back when I want them out of the way.
There's several reasons why I like the Skin Component Bags. One is that when you take a lens out, the bag can fold almost flat against your body. Below you can see it compared to the heavily padded and bulkier Lowepro lens case that I used to use. Don't get me wrong, the Lowepro bags are great too, and they really protect your gear, but having several Lowepro lens cases on my belt just made me feel a little too wide and I'd be bumping into things when trying to maneuver around a crowded room.
Another thing I like about the Think Tank bags is that the zipper pulls are non-metal. I've broken off more metal zipper pulls than I can count (probably because of all the salt air they are exposed to at the beach). I like the Think Tank design better because not only do they not eventually wear out and snap off, but they don't make a lot of noise that metal zipper pulls do when you are moving around during a church ceremony.
One of the main features that I like about the Skin Component System is the "Stealth Mode" velcro for the cover flaps.
This lets you cover up the velcro so that you can quickly open and close the bag without making that typical loud velcro ripping sound.
Each bag has a drawstring closure on the mouth of the bag as well as an integrated rain cover.
Some of their bags also have the additional drop down feature that lets you unzip the bottom of the bag and extend it. This lets you put in a lens with the hood extended so that you can whip it out, mount it to your camera, and start shooting without having to fiddle with reversing the lens hood.
Right now Think Tank is having a sale on their belt systems, so I hope you have the chance to take advantage of it. You can see the Skin Component System here. If you feel you need a belt system with more padded protection for your gear, they also have the Modular Belt System here.