rudder, helm, wheel
舵 centers on the device that steers a boat: a rudder or helm. The wheel sense is a natural extension, referring to the steering wheel that controls the rudder.
舵 combines 舟 (boat) with 它, which likely contributes the sound and may relate to the idea of steering or a curved shape. The exact historical development of 它 in this context is uncertain.
The left side is a boat 舟, and the right side 它 looks like a curved rudder with a handle. Picture the rudder attached to the boat, steering it through the water.
For ダ, imagine a rudder that goes 'da' as it hits the water with each turn: da -> ダ, steering the boat.
rudder; helm
steering (of a boat); steerage
steering (a boat); helmsman; steersman; coxswain
hydroplane (submarines); diving plane; diving rudder
starboard (side of a ship)
pull on the control stick
push on the control stick
port (side of a ship)
to steer to port
pilothouse; wheelhouse; steering house
steersman; helmsman
steering gear (ship)
steered wheel (e.g. at the front of a car); steering wheel
rudder
elevator
black marlin (Makaira indica)
self-steering (boat); automatic steering
automatic steering device; self-steering gear; autopilot
coxless four (rowing); straight four
coxless pair (rowing)