The M6 is not that great on wet salt water sand. It's great in the dry but you'll have to turn the sensitivity way down on the wet sand like you do on most every other VLF.For the wet sand I don't think any VLF works as well as the Minelab BBS machines or a PI detector. I lived and detected in the Stuart and Jensen Beach areas for 8 years and tried about every detector made down there. I finally settled on a White's IDX Pro with a BigFoot coil for the dry (M6 worked well also). Minelab Sovereign Elite and then GT for the wet. Tried a few PI's in the wet (White's Surf PI Pro, & Dual Field, Tesoro Sand Shark, and Headhunter PI) but I got tired of digging iron and the Sovereign detected about as deep without the iron. (nails, wire, washers, bolts, nuts etc from the piers.)