Servo controlled motorized fin with drone motor for paddleboard 

First attempt to build a compact and powerful servo controlled motorized fin for paddleboard. Powered by a small battery but offers a long runtime of about 4 hours at trolling speed.
Onshape model: cad.onshape.co...
Motor Used: Surpass Hobby 4120(5055) Brushless Motor 14Pole C5055 400KV
Servo: s.click.aliexp... (I don't recommend this servo but can be used as a reference)