This is a watch which has grey for its dial colour. You can swim with it, but maybe not dive or snorkle.
From OnBuy
Casio B640WB-1AEF Mixed - Black
Watch Shop
Mens Casio 'Classic' Black and LCD Plated Stainless Steel Quartz Chronograph Watch - LCD / Black
Watchhome
Casio B640WB-1AVDF Unisex Watch