fairwater planes
The fins help steer the submarine; making it be able to turn left or right.
They are actually called "planes" on a submarine and allow it to maneuver underwater. Horizontal "planes" allow the submarine to go up/down, vertical "planes" allow the submarine to go left/right.
It doesn't need fins to move forwards, but fins are used to control rolling from side to side
Stabilising fins prevent a side to side rolling motion.
what does the term stabilizing fin mean
A submarine can submerge by filling ballast and trimmer tanks with sea water. The additional weight will take the submarine down. To resurface, the submarine will blow the sea water out of the tanks using compressed air. The air in the tanks make the submarine buoyant, so it rises and floats on the surface. Though a stationary submarine can submerge in this way, it usually submerges going forward and using diving plane (fins) to steepen the dive, so getting under the surface faster.
the tail fins of a bottlenose dolphin are called flukes
The submarine is manned by the crew, and crew members are called submariners.
The 'helmsman' steers a submarine.
Fulton designed a submarine called Nautilus.
fins
The tail fins are 'flukes'. Otherwise the fin on any marine animal is "... fin" where "..,." is the adjective denoting its position on the body.