The 1955 Hawaiian submarine eruption was a submarine eruption that occurred 90 km (56 mi) northeast of Necker Island on August 20, 1955. Steaming water, water discoloration and an eruption column took place during the eruption. A possible pumice raft was also witnessed. The eruption originated about 4 km (2.5 mi) below sea level from an unnamed submarine volcano. It is probably the westernmost historical eruption within the Hawaiian Islands.