Two diaries record Hayler's activities from August 1942 through October 1944 while attached to the Pacific Fleet. The diaries detail patrols, refueling stops and maneuvers, engagements, bombardments and battles, and battle damage for each of Hayler's ships and often for ships that were nearby.
The first diary records Hayler's activities while commanding the light cruiser USS HONOLULU in both the North and South Pacific fleets. Hayler's short stay in the North Pacific was followed by various patrols in the South Pacific, where he operated mostly out of Espiritu Santo. On the HONOLULU, Hayler was attached to Task Forces 67, 8, 18, and 38 and one Task Group, 36.1, which operated under Task Force 18. While attached to Task Force 8, the HONOLULU participated in the bombardment of Kiska (Aug. 1942). The HONOLULU was attached to Task Force 67 during the Battle of Tassafaronga (Nov. 1942); Task Force 18 during Vila-Stanmore and related engagements (May 1943); and Task Group 36.1 during the New Georgia, Kula Gulf, and Kolombangara battles (July 1943). During engagements on Bougainville (Dec. 1943 - Jan. 1944), the HONOLULU was attached to Task Force 38.
The second diary records Hayler's activities beginning with his 1944 promotion to rear admiral as he was relieved of command of the HONOLULU and continuing through his taking command of Task Force 39 and relieving Rear Admiral A. S. Merrill as commander of Cruiser Division 12. Cruiser Division 12, with the Marianas bombardment group, took part in the Battle of the Philippine Sea and assisted in the bombardment, seizure, and occupation of Saipan, Guam, Tinian, Peleliu, Angaur, Ngesebus, and Ulithi islands (May - Sept. 1944). The preliminary assault group under Rear Admiral Arthur D. Struble, with Cruiser Divison 12, made landings and took Dinagat, Homonhon, and Suluan islands (Oct. 1944). This group, again with Cruiser Division 12, also participated in the Battle of Surigao Strait (Oct. 1944).
Other items include photocopied photographs of the HONOLULU and Cruiser Division 12, and temporary citations and awards issued by various admirals, which are coupled with permanent citations issued for the President by the Secretary of the Navy for Hayler's actions during World War II.