 That spring , Yorktown — along with two other naval vessels and a trio of revenue cutters — headed toward Arctic waters on 27 April to protect the great herds of seals in the Bering Sea from poachers . Traveling along the west coast of the United States , the gunboat and her crew " braced " , in Evans ' words , " at the prospect of doing something " . As at Valparaíso , Evans faced the possibility of becoming involved in an international incident arising from possible confrontations with Canadian sealers . Operating under the protection of the British crown , the latter had taken particularly heavy catches . Many American vessels put to sea under the British flag in an attempt to evade prosecution by their own government . The British agreed to help put an end to the slaughter of seals and decided upon joint action with the United States in prosecuting the poachers . About 110 schooners , large and small , made up the sealing fleet , typically " armed " with double @-@ barrelled shotguns for killing the animals and Winchester rifles for dealing with any humans who attempted to interfere . The fact that the great majority of seals killed had been female — still with young in many cases — almost doubled the toll of slain seals . As Evans noted : " the slaughter in the North Pacific was fearful " . 
