The 78-year-old East Bentleigh retiree is a regular beachcomber along the shores of Melbourne's bayside beaches with his trusty underwater metal detector looking for lost gold or silver jewellery.

Hans, who didn't want his last name published, has been treasure hunting for the past 30 years and ranges south as far as Mornington.

He reckons the sands of Seaford are ideal as metal would not sink too deep. Last Thursday he found a dog chain covered in mussels and a spoon but past hauls include gold jewellery.

"When you feel the sun shining on your back and you put the sand in the sieve and see the glint of gold it's beautiful," he said.

"Once you have been hooked, it's in the blood. And you're always looking for the one you haven't found."

Hans particularly likes finding gold rings, which he melts down to transform into chain mail jewellery.

But he also takes pride in making the beach safer by removing bottles or rubbish from the water.

A member of a Dandenong metal detector and prospectors' association, the former plumber jokes it can get competitive when a group get together to hunt for valuable metal.

"But it's really about the fun of it and the thrill of the chase."