Hello,
Looks like you have a great spot to hunt there. Nice to see such good old coins coming out of the ground in this area. I have also found a few pieces of spanish silver this year, and I am not sure yours is a reale. It appears to me that the bust is facing left. Carolus the third and fourth both face right. I cannot be sure from the photo, but it looks to me that you have found a capped bust half dime instead. You can definatly see it better than I can so I will trust your eyes, but I am wondering about it. Any chance you could measure it to the nearest milimeter? Either way, it is old, and silver, and a great find!
Anthony