we found these on the reef where witnesses say japanese used as a dock n setup camp around the area. after taking these photos, i found more and even one was imbeded on the reef. to remove it you actually need to break a bit of the reef. any idea if these were from ww2? also what is the material on the nail? is it mineral build up? doesnt look like rust. also found a bullet. 3rd photo is where we found the nails