How much of a bummer is it to get an ear infection partway through your scuba diving holiday? A big bummer, that's how much. The best treatment for an outer ear infection (a skin rash) is to stay out of the water, and the treatment for an inner ear infection is antibiotics and staying out of the water, and neither of these bode well for a hard earned holiday under the sea.
However, there's hope: like with most other things, prevention is easier than treatment. If your ears are especially sensitive, letting seawater, which contains bacteria, just sit in your ear all day creates an ideal environmental for more bacteria and fungus to grow, so you need to make sure to clean your ears out after each dive. There are ear drops on the market that you can purchase, or it's easy to make your own as well.
The best homemade ear treatment is a 50/50 mix of rubbing alcohol and white vinegar. Pour some of the mix into your ear, let it sit for a minute while you massage it around, then pour it out. The rubbing alcohol dries your ear out, while the vinegar balances the pH so that it's harder for bad bacteria and fungus to grow. You'll smell like a salad, but your ears will be fresh and clean.
If you don't have rubbing alcohol and vinegar on hand, you can also at least rinse your ears out with warm water. If you don't have access to a hot shower, mix hot and cold drinking water and pour it into your ear. The most important thing is to get rid of the salt water.
And no matter what anyone says, please don't pour hydrogen peroxide in you ear. The bubbles might feel cool, but you may be doing irreversible damage to your ear.
So there you go, it's super easy to prevent ear infections! We hope you have a wonderful holiday filled with lots of diving, and with none of that painful ear nonsense.