Been MDing about 2 months, and here in Indiana not many beaches to choose from. Our county campgrounds has a 25 acre lake, a clear water gravel pit that filled in with water back in the late 1800's. It only has about 100yds of beach so its not much. I had been wading knee deep with my Ace 250 but I didn't like useing it close to water. So I got a cheap-o underwater MD to start out with, better to have that than take a chance on ruining my 250. Figured to upgrade next year to a better UW MD. Anyway I didn't find allot in the 1-1/2 hrs I hunted, but I didn't get skunked. 3 things that I couldn't understand the signals for, was the 3 heavy pieces of rock. I assume they are some type of iron ore. In the light they have tiny particles that glittered in the light. Anyone have any idea if they are iron ore, or something else.