Proper ear care is crucial for divers to maintain a healthy ear. Earwax buildup can create a plug that traps air, leading to potential eardrum rupture due to pressure changes. It can also cause vertigo if cold water enters one ear while the other is blocked. Removing earwax is important and should be done by a medical professional when necessary. For more in-depth insights, divers can refer to a video that addresses ear and sinus issues related to scuba diving.