ActionCondition()

override bool ActionCondition	(	PlayerBase	player,
		ActionTarget	target,
		ItemBase	item )

См. определение в файле ActionStartEngineBoat.c строка 26

    {   
        HumanCommandVehicle vehCommand = player.GetCommand_Vehicle();
        if (!vehCommand)
            return false;
        
        BoatScript boat = BoatScript.Cast(vehCommand.GetTransport());
        if (boat && !boat.EngineIsOn())
        {
            if (boat.GetHealthLevel("") >= GameConstants.STATE_RUINED || boat.GetHealthLevel("Engine") >= GameConstants.STATE_RUINED)
                return false;
            
            return boat.CrewMemberIndex(player) == DayZPlayerConstants.VEHICLESEAT_DRIVER);
        }
        
        return false;
    }

Перекрестные ссылки ActionTarget, HumanCommandVehicle::GetTransport() и GameConstants::STATE_RUINED.