Looking for father- please help reunite!

My name is Amy (Dussault) Menger, and I am from Seattle, Washington. I am looking for ANY information on a free diver from the area- possibly from years ago. He is my father in law, and we haven't heard from him in many years. His son and I are trying to find him, and appreciate any help.

His name is Harry Menger, and he would be an older gentlemen- maybe in his 70's. He was a world record holding free diver in the late 1960's- probably 5th best in 1968. He lived aboard a 40+ ft power boat named, "Hardcore". He lived, worked, and dove in and near the islands, and I'm hoping someone has heard of him, or knows anything about him.

THANK YOU for your help!