Make A Submarine Help

Secret to the submarine and how to make a submarine. Now first off as u have probably read else where that submarines need to be balanced out and have a high density.
Submarines will take some practice but so easy when u get it down. First off
there are two different submarines. Those who are high density and just use weight to sink. And those that use arches to push the water down on the boat making it go underwater with a higher density.

An excellent example of this boat would be the U-Boat in the shop.
It uses those little angled things in the front to make the water push up down on the boat makeing it go underwater. 
Also there is a much easier way to make one but its rather expensive and the video is on YouTube . But I made my own and added an extra torpedo.
This one was shown on YouTube and there are many other ones. Just google easy submarine on battleship craft.
Always make sure that you level out your ship and while you add weapons it will always still go underwater. In order to do so gradually add ballasts to each side to its able to submerge under water without any difficulty. When it does so please try to make sure you are able to submerge underwater and continue to stay underwater.
When you do this you will continuously need to adjust weight throughout build. The only weapons you can use for a battleship is underwater torpedoes you can use guns on top and other type of submarines but I will post about that later. For now make it your goal to level out your ship and always make sure it is stable and able to submerge underwater. Also note that you should try to make your subs weigh 9.0 and not 1.0 for 1.0 will always sink eventually while with 9.0 you will be able to not sink and yes gradually rise but if you make your ship right, be able to dive deeper without surfacing like my ship for example which goes 50 knots easily.