Sometimes called fish boards because of their shape, they are smaller and slimmer than the ones used today.
"I thought old toys in the 70s were cars or dolls made with iron or tin. But after seeing the penny board, I knew I was wrong," says Lit Chun, 17, a Form Five student at Concordia Lutheran School.
Unlike modern versions, which usually have wooden decks up to 83cm long, penny boards are made of plastic and measure just 56cm to 69cm.
Through common friends, Lit met other enthusiasts - Edwardo Chan Tak-fu, C. M. Leung Sze-yu, Leroy Anthony Kong and Harry Yip Man-chi. In September, they formed a group called Fish for Speed (FFS), which promotes the sport in Hong Kong via Facebook and YouTube.
FFS already has 50 members, 30 of whom are active.
They usually meet in Central and Admiralty on Fridays. At night, when there is less traffic, they can skate all the way to Causeway Bay. Leroy, 16, a Form Four student at Logos Academy, says Leung taught him how to ride, and he was skating like a pro in just 15 minutes.
"Riding on the penny board gives you a very soft feeling because the wide rollers help absorb the shock," Leroy says. "It is well-designed for riding on concrete roads and pretty easy to master.
"Two months ago when I first started, I bought a cheaper model for less than HK$500. But now that I am already addicted to them, I bought a new one for several hundred dollars more."
Edwardo, meanwhile, skates to school if he doesn't feel like taking the bus. "All I need to do is place the board in my school bag when I enter the campus. Teachers are fine with that as long as I don't ride it at school," he says.
Even though the penny board is user-friendly, Sze-yu, 17, an experienced skater, takes precautions and always brings a first-aid kit.
"Skaters are advised not to wear shoes with heels or air cushions," says Sze-yu, from SWCS Chan Pak Sha School. "Wearing tight pants can also be dangerous."
Harry, 20, focuses on the beauty of the penny board.
"I started to take photos of [the skaters]. The boards are really eye-catching and cast a magic spell on us," he says. "I used to think it wasn't my thing, but once I tried it ... I couldn't resist the sport anymore."
Sadly, not everyone has as much respect for the sport. This was something Edwardo sought to address in a video that he uploaded online.
"Since it's the trendiest merchandise at the moment, many youngsters just buy the board to look stylish ... Only a few really use it for skateboarding. This is an unhealthy trend," he says in the clip.
FFS members have vowed to raise the sport's profile. And even if the board becomes outdated one day, for them, it will never lose its magic.