 Arriving at Port Townsend , Washington , on 30 April , Yorktown put to sea on 13 May , arriving at <unk> , Unalaska , one week later . Coaling there , the gunboat skirted the ice floes near the seal rookeries of the Pribilof Islands , reconnoitering the vicinity for sealers . Assisted by a revenue cutter , Yorktown guarded the passes to the Bering Sea . The crews of the patrolling American ships lacked fresh provisions but carried on in spite of the hardships imposed by both diet and climate . Fresh fish , however , proved abundant . Codfish was the staple with an occasional gourmet treat of salmon . 
