I'd say the reel is your most vulnerable piece of equipment when going salt. Find out from the manufacturer if it is salt capable...some reels are not designed to withstand the saltwater because of corrosion or abrasion.
Keep it out of the sand and water if possible.
If it starts grinding, try and clean it right away...sand can do real damage to drags.
As stated, clean everything with fresh water after usage.
Fly fishing can be very productive and fun in salt water...enjoy!