Adding to what Bruiser L said, for Contractor's sea trials (ie she's still "owned" by the Contractor), she will be under the command of a Master Mariner of the Merchant Navy.
Some of those D for DARING Class destroyers did have rather nancy names; like DELIGHT, for instance.
Airfix did a Srs 1 kit of the DARING and it somewhat pre dated the LEANDER one.