UB-3
... that when German U-boat UB-3 disappeared on her first patrol in May 1915, she was the first of her class to be lost?
... that when <a href="./German_Empire" id="mwEhw" rel="mw:WikiLink" title="German Empire">German</a> <a href="./U-boat" id="mwEh0" rel="mw:WikiLink" title="U-boat">U-boat</a> <b id="mwEh4"><a about="#mwt51" data-mw='{"parts":[{"template":{"target":{"wt":"SMU","href":"./Template:SMU"},"params":{"1":{"wt":"UB-3"},"2":{"wt":""},"3":{"wt":"2"}},"i":0}}]}' href="./SM_UB-3" id="mwEh8" rel="mw:WikiLink" title="SM UB-3" typeof="mw:Transclusion"><i>UB-3</i></a></b> disappeared on her first patrol in May 1915, she was the first of <a href="./German_Type_UB_I_submarine" id="mwEiA" rel="mw:WikiLink" title="German Type UB I submarine">her class</a> to be lost?