I found that ScrollViewer can't be concatenated, which means if it is concatenated like in your case the Grid starts under the ScrollViewer tag and in the Grid we have DataGrid and in the DataGrid again the ScrollViewer property has been set. i.e.
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="30" />
<RowDefinition Height="45" />
<RowDefinition Height="100*" />
<RowDefinition Height="105" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Label Grid.Row="0"
Grid.Column="0"
Margin="10,0,0,0"
HorizontalAlignment="Left"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Vessel: " />
<TextBox Height="30"
Width="300"
Margin="70,0,0,0"
HorizontalAlignment="Left"
BorderThickness="1,1,1,1"
IsReadOnly="True"
Name="txtVessel" />
<Label Grid.Row="0"
Grid.Column="2"
Margin="0,0,185,0"
HorizontalAlignment="Right"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Month:" />
<StackPanel Orientation="Horizontal"
Grid.Row="0"
Grid.Column="2"
Margin="0,0,0,0"
HorizontalAlignment="Right">
<ComboBox BorderThickness="2"
HorizontalAlignment="Right"
Name="CmbMonth"
VerticalAlignment="Center"
Width="90" />
<ComboBox BorderThickness="2"
HorizontalAlignment="Right"
Margin="5,0,0,0"
Name="CmbYear"
VerticalAlignment="Center"
Width="90" />
</StackPanel>
<Grid Grid.Row="1"
Grid.ColumnSpan="2">
<Grid.RowDefinitions>
<RowDefinition Height="45" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="30" />
<ColumnDefinition Width="220" />
<ColumnDefinition Width="80" />
<ColumnDefinition Width="80" />
<ColumnDefinition Width="80" />
<ColumnDefinition Width="80" />
<ColumnDefinition Width="120" />
<ColumnDefinition Width="120" />
<ColumnDefinition Width="140*" />
</Grid.ColumnDefinitions>
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="0" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="1" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="2" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="3" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="4" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="5" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="6" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="7" />
<Border BorderBrush="Black"
BorderThickness="0,1,1,1"
Grid.Row="0"
Grid.Column="8" />
<Label Grid.Row="0"
Grid.Column="1"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Item" />
<Label Grid.Row="0"
Grid.Column="2"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Maker" />
<Label Grid.Row="0"
Grid.Column="3"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Model" />
<Label Grid.Row="0"
Grid.Column="4"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content=" Part No.
Serial No." />
<Label Grid.Row="0"
Grid.Column="5"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Condition" />
<Label Grid.Row="0"
Grid.Column="6"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content=" Onboard
 Calibr/Test" />
<Label Grid.Row="0"
Grid.Column="7"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content=" Shore
 Callibration" />
<Label Grid.Row="0"
Grid.Column="8"
Margin="0,0,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Remarks" />
</Grid>
<Border Grid.Row="2"
Grid.ColumnSpan="2">
<ScrollViewer Grid.Row="2"
Grid.ColumnSpan="2"
CanContentScroll="True"
HorizontalScrollBarVisibility="Disabled"
VerticalScrollBarVisibility="Auto"
Name="ScrollViewer3"
Margin="0,0,0,0">
<Grid Name="grdOnBoardCalibrationRecord"
Margin="0,0,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="30"></ColumnDefinition>
<ColumnDefinition Width="220"></ColumnDefinition>
<ColumnDefinition Width="80"></ColumnDefinition>
<ColumnDefinition Width="80"></ColumnDefinition>
<ColumnDefinition Width="80"></ColumnDefinition>
<ColumnDefinition Width="80"></ColumnDefinition>
<ColumnDefinition Width="120"></ColumnDefinition>
<ColumnDefinition Width="120"></ColumnDefinition>
<ColumnDefinition Width="140*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<Border Grid.Column="0"
BorderThickness="1,0,1,1"
BorderBrush="Black"
Grid.RowSpan="26"></Border>
<Border Grid.Column="1"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="2"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="3"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="4"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="5"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="6"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="7"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
<Border Grid.Column="8"
BorderThickness="0,1,1,1"
Grid.RowSpan="26"></Border>
</Grid>
</ScrollViewer>
</Border>
<Grid Grid.Row="3"
Grid.ColumnSpan="2">
<Grid.RowDefinitions>
<RowDefinition Height="30"></RowDefinition>
<RowDefinition Height="30"></RowDefinition>
<RowDefinition Height="40"></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBox Grid.Row="0"
Grid.Column="0"
Height="30"
Width="300"
TextAlignment="Center"
Background="Gray"
IsReadOnly="True"
Margin="0,0,0,0"
HorizontalAlignment="Right"
VerticalAlignment="Bottom"
BorderThickness="1,1,1,1"
Name="txtChiefEngineer" />
<Label Grid.Row="1"
Grid.Column="1"
Margin="0,0,100,0"
HorizontalAlignment="Right"
VerticalAlignment="Center"
FontWeight="Bold"
Content="Chief Engineer" />
<StackPanel Orientation="Horizontal"
Grid.Row="2"
Margin="0,0,0,0">
<Label Name="lblonshorecomment"
Content=" Shore Comment : "
HorizontalAlignment="Center"
Margin="5,0,0,0"
FontWeight="Bold"
VerticalAlignment="Center"
FontFamily="Calibri"
FontStyle="Normal"
FontSize="14"></Label>
<TextBox BorderThickness="1"
FontWeight="Normal"
IsReadOnly="True"
Height="44"
Width="878"
TextWrapping="Wrap"
AcceptsReturn="True"
HorizontalAlignment="left"
Margin="0,0,0,0"
Name="txtShoreComment"
VerticalAlignment="Center" />
</StackPanel>
</Grid>
</Grid>