The law seemed to look the other way at private clubs when it shut down operations at the public establishments, for a time. I didn't see any slot machines after 1962. I remember that year specifically because our pre-law class once partied at Kurtz's Pleasure Beach at the confluence of the Patapsco River with the Chesapeake Bay. (I was surprised to find it on Google, still in operation.) One old lady, not a member of our class, nearly knocked me to the floor with her hip when I accidentally stepped up to play one of the four one-armed bandits that she was playing simultaneously.
No one seemed to care that a bunch of teenaged Sea Scouts played the slots. We waited for the adults to tire of them and then stepped in. Dunaway Walker, the yacht club's resident storyteller, who frequently cruised with us, would stand at our backs lecturing on the evils of gambling as we played. I liked his company. I invariably won under his scrutiny. He was my good luck charm, I guess. It must have vexed him, especially when I would leave and he would step up after making sure not one was watching. He would feed a couple of coins, lose, and then stalk off certain that no good would come from playing them.
My most intriguing experience with the slots came one year when a guest on one of the yacht club boats won a jackpot at every port. We became his stalkers trying to figure out what he was doing. We discussed the way he put in the coin and pulled the lever. We watched what he did with his hands as the dials were spinning. Nothing. Finally, I happened to be waiting on the porch of the boathouse at Solomon's Island, for my turn in the shower, when he arrived and won his usual jackpot. He then placed a long distance telephone call using the pay phone. He talked a long time and the operator frequently interrupted him to insert more money.
The phone rang shortly thereafter. It persisted ringing until I went and answered it. It was the operator asking for the man who had been talking on the telephone. I'm sorry, I didn't know where he had gotten off to. He definitely knew something about coin-operated machines.