Luthor uses the proximity of the beast to bathe it into flickering St.Elmos fire making the targeting a bit easier.
"Don't cast cantrips! Hit it as hard as you can! It will sink us, this is not the time to save resources!"
[sblock=Actions]
Move: keep hold of the ship
Action: cast Faerie Fire (Shark needs Dex DC 14 save or grant advantage to all attacks for the next minute)
[/sblock]