The way to do this is first to build a large, and I mean, large sub, longer and wider than the runway. After finishing constructing your sub, you can either put one runway on top of your sub or two runways, one on each side. Note: when placing runways, make sure your sub stays balanced otherwise it will tip over.
After placing the runways, add at least one carrier deck behind the runways. Then test your sub to see if you have balancing problems. If so, use different materials to balance your sub. Make sure the runways and the carrier decks are above water when the throttle is at neutral or in reverse. When everything is worked out and balanced, now you can add your planes. Warning, planes and water don't mix. If planes are in water while on carrier deck, you lose them. At the beginning of each battle, immediately send out your planes and make your sub dive as quick as possible to avoid getting hit . Make sure your sub is armed with weapons too since planes can get shot down. After the planes do their job, they will come back, but if the runway is under water, the planes will circle around your sub. If and when the planes are circling and you want to land them, make sure when you rise to the surface, the runways and carrier decks stay above water. When they land, launch them again as quick as possible. You don't have to land them since it's a risk when you have an enemy waiting for you to rise. If your sub can't do it, start over. Good luck...
After placing the runways, add at least one carrier deck behind the runways. Then test your sub to see if you have balancing problems. If so, use different materials to balance your sub. Make sure the runways and the carrier decks are above water when the throttle is at neutral or in reverse. When everything is worked out and balanced, now you can add your planes. Warning, planes and water don't mix. If planes are in water while on carrier deck, you lose them. At the beginning of each battle, immediately send out your planes and make your sub dive as quick as possible to avoid getting hit . Make sure your sub is armed with weapons too since planes can get shot down. After the planes do their job, they will come back, but if the runway is under water, the planes will circle around your sub. If and when the planes are circling and you want to land them, make sure when you rise to the surface, the runways and carrier decks stay above water. When they land, launch them again as quick as possible. You don't have to land them since it's a risk when you have an enemy waiting for you to rise. If your sub can't do it, start over. Good luck...