Back in my first years, job sites were chaotic and we mostly used hand signals. I remember once waving to my team to come over for lunch break. A rookie operator saw it from his cab and thought it meant to swing the boom. He started moving, and the load jolted a little. We all stopped and laughed once we figured out what happened. These days, with proper radios, mix-ups like that are few and far between. It sure brings back memories of how we learned on the fly back then.
We were setting steel beams on a windy site... my spotter's radio battery gave out, so he started using hand signals like back in the day. I followed along, and we got the beam placed perfect without a word. Some guys say radios are a must, but I feel knowing signals by heart is key. That day proved it, even if it was a bit silly scrambling without tech.