The paper presents new C14 and uranium series dates on Oahu and their bearing on the dating of fluctuations of sea level due to glacioeustatisin during the Wisconsinan. The −60- and −120-ft shorelines are shown to be Wisconsinan. Scuba and submersible diving has made it possible to study the submerged shorelines. Some of the submerged shorelines are notches in vertical cliffs and were not previously found by detailed soundings. The −350-ft shelf, previously thought to be a drowned wave-cut platform, proved to be a drowned coral reef. Shorelines and drowned reefs indicate stillstands below sea level at 15, 30, 60, 80, 120, 150, 185, 205, 240±, 350, 1,200 to 1,800, and 3,000 to 3,600 ft. Those above −450 ft are thought to be glacioeustatic. Those below −450 ft are the result of subsidence.