title: Letters.
authors.affiliation: a Naval Submarine Medical Research Laboratory Groton , Connecticut.
authors.forename: W L
authors.initials: WL
authors.lastname: Hunter
authors.affiliation: b Naval Diving and Salvage Training Command Panama City , Florida.
authors.forename: K M
authors.initials: KM
authors.lastname: Zwingelberg
authors.affiliation: c Montreal.
authors.forename: L
authors.initials: L
authors.lastname: Leger
authors.affiliation: d American Power Boat Association Medical Evaluation Committee Corpus Christi, Texas.
authors.forename: W C
authors.initials: WC
authors.lastname: Triplett
authors.affiliation: e Secretary to Unlimited Racing Commission Medical Committee Empire , Michigan.
authors.forename: M A
authors.initials: MA
authors.lastname: Houghton
authors.affiliation: f Portland , Oregon.
authors.forename: L
authors.initials: L
authors.lastname: Speroff