Board a ship (6)
I believe the answer is:
embark
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">board a ship</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for embark that I've seen before include "Set out (on an enterprise)" , "Put to sea" , "Set out on journey" , "Go aboard" , "Go on board, boat or plane" .)