Science: Skyscrapers At Sea

Men familiar with the sea know that when towering waves roll past a ship with their crests above the observer and their troughs yawning below, they are likely to look twice as big as they really are. Consequently mariners and seasoned ocean travelers were last week discussingexcitedly the carefully documented measurements of prodigious waves in the Pacific reported by Lieut.-Commander Ross Palmer Whitemarsh in U. S. Naval Institute Proceedings for August.

Leaving aside water walls of earthquake origin, skyscraper waves are piled up by steady gales blowing over a great expanse of deep sea. Once formed, such waves may continue their majestic roll until broken up by slackening wind or shallow water. Loftiest ocean wave mentioned in encyclopedic discussions of the subject is a 70-footer reported by the Majestic’s, officers twelve years ago. At tales of bigger ones scientists and seamen are inclined to scoff.

Bound from Manila to San Diego last year, Commander Whitemarsh found his 477-ft. navy tanker Ramapo wallowing up & down the slopes of waves the like of which he had never seen. As the speeding giants overtook him one after another, he stationed observers in various places, got out his cinecamera. While the Ramapo was borne up a windward slope, an officer on the bridge marked the top of the following wave by a point on the mast. To err on the side of caution, the crest was assumed to be on his horizontal sight line although it was unmistakably above him. The Ramapo, its stern at the base of the wave behind, was found to be tilted up at an angle 11 ° 50′. Using this angle and the distance from bridge to stern the wave-height was computed by trigonometry, and like computations were made from other observers’ measurements. The results, in good agreement, put the wave height from trough to crest at 112 ft.