Such survival suits are still in use today with the Air Force, Navy, etc. (“Poopy Suits,” we called them). This ad poses a bit of a question: what type of mechanical difficulties might necessitate “getting into cold water” some “10 miles off coast” to effect repairs to your aircraft? You would be in the open sea; what are you going to fix bobbing around like a cork?  But this ad dates from 1919; flying machines had a bad habit of suddenly not working, and one had to be ready for anything.