Hitech's new Ctrl_Q and Shift_Q makes 8inch gunning from the cruiser easy mode. Or destroying CV groups from the shore battery easy. Use sea mode from the shore battery and follow the sea mode instructions. The 5inch batteries can be aimed with sea and land mode in the same way.
Shift_Q - Land Mode
Ctrl_Q - Sea Mode
Q - Turns off both modes.
I suspect you want to hit the other CV and cruiser. Spawn into the 8inch battery and leave it at it's default postion. Press Ctrl_Q. You will get sea mode along with a yellow horizontal hash grid and a grey Mil grid cross hair. The cross hair is to emulate the ranging binoculars or scope used to determine range visa the relationship of mils to common sizes of ships at distance. For your purpose here it's used to help with lead. Most lead 12k and past will be about one full ship length from the edge of the yellow hash grid to the nose of the ship. Practice and ranging shots will give you the rest.
Swing your guns to the enemy ship so the yellow hash grid centers on it. Raise your guns until the yellow hash grid's bottom is level with the water line of the target ship. Fire a salvo and watch the hits. Adjust from there. In your range info you will notice your joystick corrections for the gun's elevation are tiny scaled in yards rather than hundreds and thousands of yards when you are in free mode. This helps you micro adjust for short misses but makes elevating the guns very slow.
Use land mode to attack shore batteries if you have visual on them. Land mode will actually raise the hash grid up the batteries hill a bit. Or shoot at fields and towns from distance in land mode by bringing up the map. Using your mouse arrow click on your target and fire. This only works if you are in range. You can determine range by clicking on the map then looking at the range HUD upper left on your screen. The far left numbers will stop at the max range possible. The right hand range is your actual range from your location to where you clicked on the map.
To better use the map if you are not visually using the yellow hash grid at short range to shell a town or field. Go to zoom with your map open. Then use the maps zoom to increase the size of the field or town. Then click a grid walk as you fire salvos into the target. Hits will show in the text buffer if you destroy anything.