I have an IG concrete pool. There is currently caulking between the ceramic tile (the tile at the water line) and the coping (I've seen it called decking and top cap). At any rate, the caulking needs to be replaced. This area is always wet when the pool is in use, but rarely is completed submerged. The gap is approximately 1/2" wide. I'm assuming the existing caulk should be replaced with an equivalent caulking. Anyone have any recommendations on what type, what works best? Thanks in advance for your responce and help.

Scott