I have been booked to do a beach wedding in May. What is the best way to guard against sand and moisture (spray)? What other concerns should I be prepared for as opposed to any other outdoor event?

Thanks in advance for your help.

When I've had t odo beach stuff I take some plastic wrap or kitchen wrap (saran wrap) or a plastic garbage bag and "seal the camera". Oh yeah, gaffers tape to seal the seams.
The camera did seem to run a little hot but it's not for a long period of time so I never really worried about it.

As for some other stuff to watch for, the wind. It'll kill your audio. Make sure you have some sort of wind screen and depending on the lav mic perhaps you can hide it and not lose anything as far as vocal quality. Countryman B6 and EMWs work well for that.

Watch the lighting closely-sun glimmering off the beach can throw the exposure and be aware of backlighting.

Someone had a post somewhere all about beach weddings. I can't remember who it was but they do mostly beach weddings.I guess living in Hawai'i you get that a lot.
Have fun
Don

I'd deal with those hardships if I could live in Hawaii. ;o)