Welcome from White Plains, New York! Your question is a common one that is a bit difficult to answer. Much depends on your budget, as a "low cost" Multi-frequency VLF metal detector that will work well in a saltwater environment and in dry sand and dirt, starts around $1,100.00. If you forget about the wet saltwater sand and just stay in dry sand and the woods, you can get started for $200.00with a single-frequency Very Low Frequency detector. Do your due dilligence!