#18 in the Tom Swift Jr. series. Grosset and Dunlap hardcover publication. Copyright 1961. Print year is estimated at 1966, because the last title on the rear cover is #27 Subocean Geotron, published in 1966. Very good book with excellent spine and hinges. Black and white space lab endpapers. No writing/markings. Very good corners. In this one, Tom develops an artificial lung that extracts dissolved oxygen from water, eliminating the weight and bulkiness of back tanks for underwater divers, plus an anti-detection jetmarine, to foil an enemy stealth submarine in his mission to help the Navy recover a probe missile. The race is on between the Navy and the enemy to retrieve this probe with valuable scientific data inside. (TS18K)