[fred cook]

Found this:

David "Salt" Walther (November 22, 1947 – December 27, 2012[1]) was a driver in the USAC and CART Championship Car series. He also drove NASCAR stock cars, unlimited hydroplane boats, and was a car owner in USAC.
He was the son of George Walther, owner of Dayton Steel Foundry, who fielded Indy 500 cars for Juan Manuel Fangio in 1958 and Mike Magill in 1959. His brother, George "Skipp" Walther III, was fatally injured while trying to qualify as an Unlimited driver in Miami, Florida, in 1974.[2]
David Walther was given the nickname "Salt" during his teen years while racing boats, and is one of only eight unlimited hydroplane drivers to qualify for the Indy 500.