Used to get swimmer's ear all the time as a kid. The simple solution is to put a little isopropyl in your ears after you get out. It gets the water out and makes the environment too hostile for bacteria to take hold.
Quarry swimming is special, but sadly frowned upon more and more nowadays. A friend and I sneaked into one up around Cape Ann years ago and got ushered out by the law.
Speaking of special, I got back to Fishers yesterday and is the water is just beautiful in the Sound right now. Spent an hour just floating on the sandbar. Very few jellyfish. Neighbors were out with their kids on paddle-boards and setting up tables on their dock for a dinner party. Just a very summery scene.