You sold your sand shark with a life time warrant and your thinking about buy Mk2 with 2 year warrant. Are you nuts ?? You want an VLF, don't buy an AT PRO. Don't get me wrong, the AT PRO is a very good VLF detector for fresh water only. Or you can buy an excel 2, very good detector in fresh or salt water, but cost 2.5 time more than all 3 of the other detectors. you can buy the AT PRO ,sand shark and Sea hunter mk2 for under $640. The excel 2 $1500.