This bay [Sequim] opens on the Strait of Juan de Fuca and is now known as Washington Harbor. (Meany, p. 335). These geographic names used by Kautz generally had their origin with either the Vancouver Expedition of 1792 or the Wilkes explorations of 1841.
According to OpenStreetMap and Wikipedia, the name is Sequim Bay, which is not far from the spelling used by Kautz in his diary. According to Wikidata, Washington Harbor is an alternate name for Sequim Bay.